Inorganica Chimica Acta 473 (2018) 152–159

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Inorganica Chimica Acta

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Research paper

Accurate DFT studies on crystalline network formation of a new Co(II)complex bearing 8-aminoquinoline

https://doi.org/10.1016/j.ica.2017.12.0330020-1693/� 2017 Elsevier B.V. All rights reserved.

⇑ Corresponding author.E-mail address: mirzaeesh@um.ac.ir (M. Mirzaei).

Zahra Rahmati a, Masoud Mirzaei a,⇑, Mohammad Chahkandi b, Joel T. Mague caDepartment of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad 917751436, IranbDepartment of Chemistry, Hakim Sabzevari University, Sabzevar 96179-76487, IrancDepartment of Chemistry, Tulane University, New Orleans, LA 70118, USA

a r t i c l e i n f o

Article history:Received 25 August 2017Received in revised form 22 November 2017Accepted 27 December 2017Available online 28 December 2017

Keywords:Cis-[Co(8-aq)2(NCS)2]8-AminoquinolineDFT-DNon-covalent interactionBinding energy

a b s t r a c t

As a continuation of our studies on the coordination chemistry of 8-aminoquinoline (8-aq) and relatednitrogen-containing heterocyclic ligands, we report the synthesis and crystal structure of a new complexof formula cis-[Co(8-aq)2(NCS)2] (1) by slow evaporation of an aqueous ethanolic solution containing amixture of 8-aq, KSCN, and Co(NO3)2�6H2O. As expected, the 8-aq ligand chelates to the metal with theresulting coordination sphere being distorted octahedron. Examination of the packing of 1 in the crystaltogether with the results of high level DFT-D/B3LYP calculations indicate the packing is stabilized by non-classical intermolecular N–H� � �S, N–H� � �C, C–H� � �N, and C–H� � �S hydrogen bonds (HBs) together with p-stacking interactions. It should be noted that dispersion corrected density functional theory (DFT-D) cal-culations of the binding energy of non-covalent interactions prove that N–H� � �S HBs govern the forma-tion of the crystalline 3D network.

� 2017 Elsevier B.V. All rights reserved.

1. Introduction

Crystal engineering using intermolecular interactions designsand controls the network structures of organic and metal-organiccompounds bearing desired and useful properties like magnetism[1], luminescence [2], and nonlinear optics [3]. This field hasgreatly expanded [4–8] because of the development of newsupramolecular structures with useful functional and physico-chemical properties [9,10]. There are molecular multifunctionali-ties with O–, N–, and S–donors such as amino, imino, carbonyl,isothiocyanate, and carboxylate groups [11–13], that create newsupramolecular structures having different dimensionalities [14–16]. To achieve this, different non-covalent interactions like hydro-gen bonds (HBs), p-stacking, and various types of van der Waals[17] interactions are employed [18–20]. The coordination chem-istry of nitrogen-containing heterocyclic ligands has a long historyand is dominated by complexes of pyridine, 1,2-diaminoethane,2,20-bipyridine, 1,10-phenanthroline, their derivatives and a widevariety of related molecules [21]. Considerably fewer examples oftransition metal complexes of 8-aminoquinoline (8-aq) are knownbut there is growing interest in these and those with derivatives of8-aq because of their antiprotozoal activities and other medicinal

properties [22–28]. With the amino group and an extended p-sys-tem, 8-aq complexes present the possibility of varied intermolecu-lar interactions in the crystal which could produce interesting solidstate properties. Indeed, the construction of crystal structures con-taining organic and metal-organic species with useful propertiessuch as luminescence, non-linear optics, and magnetism rely onsuch interactions to be successful [29]. In surveying the transitionmetal complexes of 8-aq and its derivatives whose structures havebeen determined, we were struck by the small number containingcobalt and that, of the six complexes containing 8-aq itself, onlytwo were monomeric, octahedral complexes [30–32]. In this work,we report a new member of this limited inventory, namely cis-[Co(8-aq)2(NCS)2] (1), and describe interesting molecular and packingfeatures studied experimentally and theoretically (see Fig. S1; CSD,Version 5.37, May 2016). It has been shown that theoretical meth-ods can be a reliable complement to experimental results, provid-ing a wider view of structure investigations, as well as vibrationalfrequencies, binding energies of intermolecular bonds and overallstabilization energies, which can aid in designing the desired com-pounds [33]. To this end, the network structure of 1 using DFT-D/B3LYP computational methods has been studied. In addition, thenon-covalent interactions forming the crystalline packing, the sta-bilization energies, and their interplaying effects, using 1 as mono-mer (1-mon, see Section 3.2) are described.

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Table 1Single crystal data and the details of refinement of structure 1.

Parameters Co(8-aq)2(SCN)2

Chemical formula C20H16CoN6S2Mr 463.44Crystal system, space group Orthorhombic, Pbcaa, b, c (Å) 8.4259(6), 14.2810(9), 31.639(2)a = b = c (�) 90Volume (Å3) 3807.1(4)Z 8Radiation type Cu KaAbsorption coefficient (mm�1) 9.285Crystal size (mm) 0.05 � 0.008 � 0.001Data collectionDiffractometer Bruker D8 VentureAbsorption correction Multi-scan (SADABS; Bruker, 2012)Temperature (K) 100(2) KDensity 1.617 g/cm3

RefinementGoodness of fit on F2 1.015No. of reflections 11087F(0 0 0) 1896Final R indexes [I � 2r (I)] R1 = 0.1198, wR2 = 0.2870Final R indexes [all data] R1 = 0.1750, wR2 = 0.3448Largest diff. peak/hole (e �3) 1.059 and �1.336H-atom treatment H-atom parameters constrained

Fig. 1. (Above) ORTEP drawings of compound 1 with the numbering scheme.Thermal ellipsoids shown at the 50% probability level. (Below) Optimized B3LYP/LANL2DZ/6–311+G (d, p) structure of 1-mon.

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2. Experimental

2.1. Materials and measurements

All chemicals used in this work were analytical A.R grade. 8-aminoquinoline (99%), cobalt(II) nitrate hexahydrate, and potas-sium isothiocyanate (99%) were purchased from Merck Companyand used without further purification. The X-ray data wereobtained on a Bruker D8 Venture diffractometer.

2.2. Synthesis of [Co(8-aq)2(NCS)2]

A solution of 8-aq (20 mg, 0.13 mmol) in 3 mL of ethanol wasadded to a solution of KSCN (15 mg, 0.15 mmol) in 5 mL of distilledwater. The mixture was stirred for 10 min and then was added to asolution of Co(NO3)2�6H2O (63 mg, 0.21 mmol) in 10 mL of distilledwater. The resulting pink solution was stirred at 40–50 �C for onehour. By slow evaporation of the solvent, at room temperature, finebrown crystals of 1 (Yield: 12 mg, 37.33% based on 8-aq) wereobtained after 2 weeks. The synthesis of the titled complex pro-ceeded in a straightforward manner to produce X-ray quality crys-tals after recrystallization. Anal. Calc. for C20H16CoN6S2: C, 51.78;H, 3.45; N, 18.12%. Found: C, 51.28; H, 3.34; N, 18.07%. IR (KBr pel-let, cm�1) m: 3200 & 3115 (N–H), 2075 (C–N)SCN, 1505 & 1470 (C–C), 1395 (C@N), 1010 (C–N).M.p. 270 �C

2.3. Structure determination

A suitable crystal of the title complex was mounted on a thinpolymer loop with a drop of heavy oil and placed on the diffrac-tometer in the cold nitrogen stream provided by an Oxford Cryo-stream 700 cooler. A hemisphere of intensity data to a resolutionof 1.0 Å was collected using 606 scans in x (0.5�/scan; 120 s./scan)using the QUEEN strategy in the APEX2 [34] program suite. The rawdata were reduced to F2 values using the SAINT software [34] and aglobal refinement of unit cell parameters employing 2790 reflec-tions chosen from the full data set was performed. Multiple mea-surements of equivalent reflections provided the basis for anempirical absorption correction as well as a correction for any crys-tal deterioration during the data collection (SADABS) [34]. Thestructure was solved by direct methods and refined by full-matrix,least-squares procedures using the SHELXTL program package [34].Hydrogen atoms were placed in calculated positions and includedas riding contributions with isotropic displacement parameterstied to those of the attached non-hydrogen atoms (see Table 1).

2.4. Computational details

The applied calculations have been done using B3LYP/LANL2DZ/6-311+g(d,p) level of the DFT method by means of theGaussian 09 program [35]. In order to evaluate the binding ener-gies of the non-covalent interactions and the stabilization energyof the resulting network, the following procedure was applied:First, for the geometry optimization of 1 (CoC20H16N6S2) as thesmallest independent unit (1-mon, see Fig. 1) the positions ofthe H atoms were optimized while the positions of non-hydrogenatoms, obtained from the crystal structure, were fixed at the crys-tallographic coordinates. Then, the larger fragments of 1-mon (1-frag1, 1-frag2, 1-frag3, and 1-frag4) and the final network (1-net) bearing all involved non-covalent interactions were optimizedand frequency calculations were done. For all of the DFT calcula-tions, the hybrid functional B3LYP [34–36] level was employedwith the LANL2DZ basis set for the cobalt atom and the triple—f6-311 + G(d, p) basis set for all other atoms. It has been proven thattheoretical level of B3LYP provides reliable energetic data of a wide

variety of H–bonded structures [29,30,39–42]. The computedenergies of those interactions using the B3LYP-D [43] functionalas dispersion-corrected DFT employing the basis set superpositionerror (BSSE) [44], were corrected. Some of the experimental and

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theoretical geometric parameters of 1-mon are listed in Table 2.Selected theoretical geometrical parameters and the related bind-ing energies of the non-covalent interactions about 1-net are sum-marized and compared in Tables 2 and 3.

3. Results and discussion

3.1. Synthesis

Organic and inorganic ligands have different electron donorproperty and size. Therefore, these two types of ligands are coordi-nated to a metal ion in special conditions. A look at the literatureshows that the main strategy for the synthesis of mixed ligandcomplexes containing organic and inorganic short-range ligandsis the use of mild conditions since the hard conditions (high tem-perature and high pressures) favor the formation of the complexwith an organic ligand [13b]. It seems at low temperatures andambient pressure, both ligands have enough time for suitableorientation and can coordinate to metal ions simultaneously.Similarly, compound 1 is prepared at 40 �C, ambient pressure andshort reaction time (1 h).

3.2. Experimental and theoretical crystal description of 1

Pertinent crystallographic data are presented in Table 1. Thebest crystals were extremely small, less than 0.1 mm in all dimen-sions, and did not diffract strongly so that even with the longestreasonable exposure times the best resolution that could beobtained for the data was 1.0 Å. Thus, although the structuraland supramolecular features obtained are reasonably well deter-mined, the quality of the structure is low. Selected crystallographicand theoretical optimized geometrical parameters of 1 are col-lected in Table 2. Selected bond lengths and angles together withthose of the hydrogen bonding interactions are gathered in TablesS1–S3. The asymmetric unit of the title compound is a neutralmononuclear complex with [Co(8-aq)2(NCS)2] formula and molec-ular weight of 463.44 gmol�1. The Co(II) center is six-coordinatedthrough bonding to the thiocyanate ligands and amine and iminenitrogens of two 8-aq ligands (cf. Fig. 1). However, there are signif-

Table 2Selected experimental and optimized B3LYP/LANL2DZ/6–311 + G (d, p) atomic distances (

Compound 1: CoC20H16N6S2

Experimental Calculated Experime

Co1–N1 2.121(11) 1.982 N1�Co1–N3 161.67(4Co1–N2 2.165(11) 2.209 N1�Co1–N4 93.67(4)Co1–N3 2.123(11) 2.087 N1�Co1–N5 95.80(4)Co1–N4 2.202(12) 3.232 N1�Co1–N6 98.40(4)Co1–N5 2.093(13) 1.934 N2�Co1–N3 89.41(4)Co1–N6 2.079(13) 1.933 N2�Co1–N4 101.33(5N5�C19 1.129(17) 1.180 N2�Co1–N5 90.41(5)N6�C20 1.133(14) 1.184 N2�Co1–N6 174.52(6C19�S1 1.681(16) 1.622 N3�Co1–N4 76.71(3)C20�S2 1.674(15) 1.615 N3�Co1–N5 96.62(4)N1�Co1–N2 77.12(4) 80.69 N3�Co1–N6 95.74(4)

Table 3Selected experimental and calculated HBs for 1-net.

D—H� � �A D—H (Å) H� � �A (Å)N2�H2A���S1v 0.910(e), 1.08(c) 2.71 (e), 2.760(N2�H2B���S2v 0.910(e), 1.06(c) 2.54 (e), 2.591(N4�H4B���S1i 0.910(e), 1.07(c) 2.69 (e), 2.739(C10�H10���S2v 0.949(e), 1.07(c) 2.93 (e), 2.996(C11�H11���S2xi 0.951(e), 1.06(c) 2.96 (e), 3.027(

icant deviations from ideal octahedral geometry, e.g., because ofthe restricted bite angles of the 8-aq ligand the angles N1–Co1–N2 and N3–Co1–N4 are considerably less than 90�. Also, the transangle N2–Co1–N6 is closest to linear but the other two are consid-erably less and likely the result of being associated with the 8-aqligand that lies in the equatorial plane (defined here by N1, N4,N3 and N5). The Co–N distances and N–Co–N angles involvingthe 8-aq ligand compare favorably with those reported for [Co(8-aq)(hfac)2] (hfac = hexafluoroacetylacetonate) [32]. In the crystal,N4–H4B� � �S1 HBs generate zig-zag chains running along the a-axisdirection. The chains are tied together by N2–H2A� � �S1 and N2–H4B� � �S2 HBs (Fig. 2) to form sheets parallel to [0 0 1]. The 3Dsupramolecular structure is assembled by two sets of slipped p-stacking interactions (Fig. 3). One of these involves pairwise,head–to-tail interactions between the 8-aq ligands containing N3and N4 in molecules related by centers of symmetry. In this set,the centroid-to-centroid distance is 3.702(8) Å while the dihedralangle between the mean ligand planes is 3.6(7)�. The other isbetween the pyridine ring of the ligand containing N1 and N2 withthe benzene ring of the same ligand in an adjacent moleculerelated by the a glide plane which generates a stepped motif witha centroid-to-centroid distance of 3.732(8) Å and a dihedral angleof 4.6(7)�. Since no symmetry constraints within the geometryoptimization were applied, several significant differences of geo-metrical parameters of experimental and theoretical structuresoccurred. Actually, the optimized structure of the isolated gasphase monomeric unit of 1 has 5-coordinated geometry for theCo(II) metal center with a 3.232 Å distance for Co–N4 (Exp.:2.202 Å).

Computer programs: APEX2 (Bruker, 2012), SAINT (Bruker,2012), SHELXTL (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008),ORTEP-3 for Windows (Farrugia, 1997).

(cf. Fig. 1). There are other structural parameter differences withthe largest ones involving the N2–Co–N6 and N5-Co–N6 bondangles and the C1–N1–C9–C8, C10–N3–C18–C17 and H4A–N4–Co–N6 torsion angles which are 70.45� and 79.77� and 356.50�,349.40� and 147.82�, respectively (Table 2). The powerful drivingforce for these structural changes is the formation of a strongintra-molecular N4–H4A� � �N6 HB (1.932 Å). The optimized struc-ture of 1 shows that the 8-aq ligand has tried to close the amine

Å) and angles (�) for 1-mon.

ntal Calculated Experimental Calculated

) 173.67 N4�Co1–N5 166.34(4) 128.03123.13 N4�Co1–N6 82.03(5) 63.4889.00 N5�Co1–N6 86.91(5) 166.6888.61 Co1�N5–S1 161.82(3) 171.47105.35 Co1�N6–S2 178.10(4) 160.20

) 62.19 C1–N1–C9–C8 177.16(3) �179.3488.46 C10–N3–C18–C17 177.12(5) �172.28

) 104.07 C8–N2–Co1–N4 �109.93(3) �129.8062.37 H4A–N4–Co1–N6 �147.11(1) 0.70589.28 C1–N1–Co1–N6 9.64(6) �77.7891.68 C10–N3–Co1–N6 108.06(4) 113.63

D���A (Å) D—H� � �A (�)c) 3.524(e), 3.620(c) 148.7(e), 159.1(c)c) 3.443(e), 3.472 (c) 174.3(e), 173.5(c)c) 3.528 (e), 3.639 (c) 152.7(e), 163.0(c)c) 3.799 (e), 3.826 (c) 153.1(e), 156.0(c)c) 3.706 (e), 3.885 (c) 136.8 (e), 143.5(c)

Fig. 2. Detail of the N–H� � �S hydrogen bonding (symmetry codes: (i) �1 + x, y, z; (ii) 1 + x, y, z; (iii) 2 + x, y, z; (iv) ½�x, �½+y, z; (v) 1.5�x, �½+y, z; (vi) 2.5-x, �½+y, z; (vii)3.5�x, �½+y, z).

Fig. 3. Detail of the slipped p-stacking interactions (symmetry codes: (viii) 1-x, 1-y, 1-z; (ix) �½+x, y, 1.5-z; (x) ½+x, y, 1.5-z).

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moiety with the nitrogen atom of isothiocyanate ligand causing thechange in the structural parameters. As part of this effort, oneisothiocyanate ligand moves somewhat away from the trans posi-tion (N5–Co–N6 166.68�). Finally, the huge difference of experi-mental and theoretical C1–N1–C9–C8 torsion angle can be

Table 4Comparison of cis/trans configuration within some 8-aq complexes.

Compounds Accompanying anion (X�)

1 SCN�

[Co2(NCS)2(AP)2(8-aq)] SCN�

[Zn(8-aq)2(SCN)2] SCN�

[Cd(8-aq)2(SCN)2] SCN�

[Mn(8-aq)2(SCN)2] SCN�

[Cd(8-aq)(SCN)2]n SCN�

[Fe(8-aq)2(l-N(CN)2)]n N(CN)2[Mn(8-aq)2I2] I�

[Cd(8-aq)2I2] I�

[Cd(8-aq)(N3)2]n N3�

[Cd2(l-Cl)4(8-aq)2]n Cl�

[Cu(8-aq)2Cl(H2O)]�Cl�H2O Cl�[Cu(8-aq)2(NO3)(H2O)].NO3 NO3�

Abbreviation: AP = 2-(8-aminoquinolino)-4,6-di-tert-butylphenol.

explained that Co–N1 being stronger in the first one (for morecomparative information see Table 2). Comparison of the structureof 1 and the crystal structures present in Table 4 illustrates that theaccompanying anions play a vital role in the observed geometry ofthe M(8-aq)2 complexes. The quinoline system favors synergic

Coordination mode Configuration Ref

Terminal ligand cis This workTerminal ligand cis 46Terminal ligand cis 47Terminal ligand cis 48Terminal ligand cis 30Bridging ligand trans 47Bridging ligand trans 49Terminal ligand cis 30Terminal ligand cis 30Bridging ligand trans 48Bridging ligand trans 45Terminal ligand trans 30Terminal ligand trans 30

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back-bonding, therefore its presence as a basal ligand would beenergetically more favorable than as an apical ligand to favor thep-acceptor mechanism. Consequently, in most 8-aq complexes

Fig. 4. The theoretical models used to evaluate the different non-covalent interactionseffective interactions of the mentioned fragment are separated into parts A and B.

the ligand lies in a basal plane and is almost coplanar with themetal center. Interestingly, the nature and coordination mode ofinorganic anionic coligands such as Cl�, Br�, I�, N3� and SCN�

in selected fragments of compound (distances in Å). Just for more clarity, observed

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influence this geometry. For example, complexes involving two Cl�

and N3� anions are 1D coordination polymers wherein these anionsact as bridging ligands with trans configuration and two 8-aq arealmost coplanar, while I� anion coordinates to MII ions as a mon-odentate terminal ligand with cis configuration and two 8-aq areperpendicular to each other. Meanwhile, SCN� anion shows dualbehavior. Where it coordinates to metal center as a monodentateterminal ligand, two 8-aq are perpendicular to each other andthe complex is in cis configuration. On the contrary, complexescontaining bridging SCN� show trans configuration with coplanar8-aq ligands. Additionally, presence of one anionic coligand andH2O in M(8-aq)2 complexes lead to trans configuration. These find-ings determine that differences in the size of accompanying anionsand their coordination modes in addition to the reaction conditionscan change geometry of M(8-aq)2 complexes [45–49].

3.3. Crystal packing constructed by Non-covalent interactions:Theoretical consideration

A coordination compound can make the related crystalline net-work through the self-assembling of the pertinent monomer con-nected by inter-molecular non-covalent interactions (see Figs. 2and 3). In recent years, DFT calculations have provided the meansfor estimating the binding energies of these non-covalent interac-tions [29,30,37–41,50] and we use these to determine the stabi-lization energy of the resulting crystalline network as detailedbelow. First, the independent monomer of 1 (1-mon) was fullyoptimized. Then, the same optimization conditions using theB3LYP–D dispersion functional [43] upon the structures of the frag-ments (1-frag1 to 1-frag4) and the overall network (1-net) includ-ing all non-covalent interactions were applied. At the end, thebinding energy of every non-covalent interaction that links themonomers to form the fragments and the network and also the sta-bilization energy of 1-net were determined (see Figs. 4 and 5).Regarding the Section 3.1 comparing of the optimized and experi-

Fig. 5. Formation energy of 1-net (for more clarity just the interacti

mental structures of 1, the intra-molecular N4–H4A� � �N6 HB(1.932 Å) formation led to the optimized structure being stabilizedby 28.73 kJ mol–1 over the experimental structure (see Fig. 1). Formore clarity, in each fragment just a kind of non-covalent interac-tion was discussed. The 1-frag1 includes seven monomers (hep-tamer) that are constrained by three sets of N2�H2A���S1 (2.757Å), N4 � H4B���S1 (2.728 Å), N4�H4A���S2 (2.779 Å) andN2�H2B���S2 (2.588 Å) HBs and one set of N2 � H2A���S1 (2.685Å), N4�H4B���S1 (2.663 Å), N4�H4A���S2 (2.717 Å) andN2�H2B���S2 (2.499 Å) HBs resulting in a stabilization energy ofDE1 = �312.46 kJ mol�1. The tetramer of 1-frag2 bears a doubleset of C11–H11���S2 (2.937 Å) and C12 � H12���S1 (2.873 Å) HBsand a C10–H10���S2 (2.910 Å) HB leading to a stabilization energyof DE2 = �63.33 kJ mol�1. The next tetramer fragment, 1-frag3,has been stabilized by DE3 = �72.76 kJ mol�1 from a double setof N2�H2B���C20 (2.796 Å) and C7�H7���N6 (2.835 Å) HBs and aC3�H3���N5 (2.727 Å) HB. The stacking interactions C�H� � �p andp���p establish the last pentamer fragment (1-frag4) with a bindingenergy of DE4 = �152.48 kJ mol�1 as the sum of a double set ofC11�H11���p(Ph) (3.415 Å), C12 � H12���p(Ph) (3.831 Å),C3�H3���p(Ph) (3.564 Å), C6�H6���p(Ph) (3.491 Å), C2�H2���p(py)(3.406 Å), C5�H5���p(py) (3.730 Å), pPh���ppy (3.679 Å) and pPh���ppy(3.709 Å) interactions as well as a C15�H15���p(py) (3.048 Å) inter-action (see Fig. 4).

In the structure of 1-net there are three sets of N2–H2A���S1(2.732 Å), N4�H4B���S1 (2.708 Å), N4�H4A���S2 (2.756 Å) andN2�H2B���S2 (2.561 Å) HBs, a double set of C11�H11���S2 (3.027Å), C12�H12���S1 (2.933 Å), N2�H2B���C20 (2.898 Å), C7�H7���N6(2.859 Å) HBs, a double set of C11�H11���p(Ph) (3.428 Å),C12�H12���p(Ph) (3.848 Å), C3�H3���p(Ph) (3.573 Å), C6�H6���p(Ph)(3.508 Å), C2�H2���p(py) (3.412 Å), C5�H5���p(py) (3.741 Å), pPh���ppy(3.687 Å) and pPh���ppy (3.720 Å) interactions and one set ofN2�H2A���S1 (2.760 Å), N4�H4B���S1 (2.739 Å), N4�H4A���S2(2.825 Å), N2�H2B���S2 (2.591 Å), C10�H10���S2 (2.996 Å) andC3�H3���N5 (2.741 Å) HBs as well as a C15�H15���p(py) (3.054 Å)

ons with interplaying effect have been shown.) (distances in Å).

Table 5The calculated non-covalent interactions distances (Ǻ), angles (�), and their bindingenergies (kJ mol–1) of 1-net.

d(H� � �A) < (DHA) Binding EnergyN2�H2A���S1 2.732 152.9 �19.82N4�H4B���S1 2.708 161.03 �20.11N4�H4A���S2 2.756 128.12 �18.65N2�H2B���S2 2.561 176.39 �21.19C11�H11���S2 3.027 143.53 �11.43C12�H12���S1 2.933 158.7 �12.74N2�H2B���C20 2.898 147.24 �13.89C7�H7���N6 2.859 162.9 �13.60C11�H11���p(Ph) 3.428 82.03 �8.21C12�H12���p(Ph) 3.848 72.28 �7.79C3�H3���p(Ph) 3.573 76.14 �8.76C6�H6���p(Ph) 3.508 98.56 �9.04C2�H2���p(py) 3.412 95.23 �9.15C5�H5���p(py) 3.741 76.81 �7.93pPh���ppy 3.687 180 �6.92pPh���ppy 3.72 180 �7.38N2�H2A���S1 2.76 159.08 �18.29N4�H4B���S1 2.739 162.97 �18.86N4�H4A���S2 2.825 136.21 �17.52N2�H2B���S2 2.591 173.46 �20.32C10�H10���S2 2.996 155.96 �12.09C3�H3���N5 2.741 141.57 �12.15C15�H15���p(py) 3.054 98.75 �10.88StabilizationEnergy

Interaction types

DE1 � 312.46 3 � (N2�H2A���S1 (2.757 Å), N4�H4B���S1 (2.728 Å),N4�H4A���S2 (2.779 Å), N2�H2B���S2 (2.588 Å)*) +N2�H2A���S1 (2.685 Å), N4�H4B���S1 (2.663 Å) +N4�H4A���S2 (2.717 Å) + N2�H2B���S2 (2.499 Å)

DE2 � 63.33 2 � (C11�H11���S2 (2.937 Å), C12�H12���S1 (2.873 Å)) +C10�H10���S2 (2.910 Å)

DE3 � 72.76 2 � (N2�H2B���C20 (2.796 Å) and C7�H7���N6 (2.835 Å)) +C3�H3���N5 (2.727 Å)

DE4 � 152.48 2 � (C11�H11���p(Ph) (3.415 Å), C12�H12���p(Ph) (3.831 Å),C3�H3���p(Ph) (3.564 Å), C6�H6���p(Ph) (3.491 Å),C2�H2���p(py) (3.406 Å), C5�H5���p(py) (3.730 Å), pPh���ppy(3.679 Å), and pPh���ppy (3.709 Å)) + C15�H15���p(py) (3.048Å)

DEtot �569.50

3 � (N2�H2A���S1 (2.732 Å), N4�H4B���S1 (2.708 Å),N4�H4A���S2 (2.756 Å), N2�H2B���S2 (2.561 Å)) + 2 �(C11�H11���S2 (3.027 Å), C12�H12���S1 (2.933 Å),N2�H2B���C20 (2.898 Å)*, C7�H7���N6 (2.859 Å),C11�H11���p(Ph) (3.428 Å), C12�H12���p(Ph) (3.848 Å),C3�H3���p(Ph) (3.573 Å), C6�H6���p(Ph) (3.508 Å),C2�H2���p(py) (3.412 Å), C5�H5���p(py) (3.741 Å), pPh���ppy(3.687 Å), pPh���ppy (3.720 Å)) + N2�H2A���S1 (2.760 Å) +N4�H4B���S1 (2.739 Å) + N4�H4A���S2 (2.825 Å) +N2�H2B���S2 (2.591 Å) + C10�H10���S2 (2.996 Å)* +C3�H3���N5 (2.741 Å) + C15�H15���p(py) (3.054 Å)

*The weakened interactions by diminutive effects shown as underlined format.

Scheme 1. Spatial arrangement of interacting fragments in assisting (Type A) anddebilitating (Type B and C) HBs. D and A denote donor and acceptor sites.

158 Z. Rahmati et al. / Inorganica Chimica Acta 473 (2018) 152–159

interaction that stabilize 1-net by DEtot = �569.5 kJ mol�1 (seeTable 5 and Fig. 5). However, for more clarity, just interactions withinterplaying effects have been shown in Fig. 5. Symmetry codes: (i)�1 + x, y, z; (v) 1.5�x, �½+y, z; (xi) ½+x, 1.5�y, 1�z)). e: experi-mental, c: calculated.

Consideration of Figs. 4 and 5 and Table 5 shows that the stron-ger and more abundant HBs govern the packing in comparisonwith the stacking interactions. However, for a more reliable deter-

mination of the stabilization energy of the network, theoreticalmethods should calculate the interplaying effect of all involvednon-covalent bonds [29,30,39,40,50,51]. It should be consideredthat various interactions with different donor–acceptor (D–A)atoms can show interplaying effect leading to weakening or rein-forcement of each other’s influence in the stabilization energy ofthe pertinent network. If one atom simultaneously participates intwo or more HBs that have different character (Lewis base andacid), the HBs should be reinforced (see Scheme 1, type A). Whenit plays the same role in different HBs, they have a diminutiveeffect which leads to a weakening of both (Scheme 1, types Band C) [29,30,39–41].

The network structure of 1 shows diminutive effects mainlybetween some N–H� � �S and C�H� � �S interactions. Actually, in 1-frag1, the couple N2�H2A���S1 (2.757 Å) and N4�H4B���S1 (2.728Å) and the couple N4�H4A���S2 (2.779 Å) and N2�H2B���S2(2.588 Å) weaken each other because S1 and S2 are shared as Lewisbases in these couples of HBs. Therefore, their bond length, com-pared to experimental values, become longer by 0.043, 0.034,0.035, and 0.051 Å, respectively (see Fig. 4 and Table 5). Also, thesame interplaying effect is observed in the optimized structure of1-net as three sets of HBs can be classified (see Fig. 5).N2�H2A���S1 (2.760 Å), N4�H4B���S1 (2.739 Å), and C12�H12���S1(2.933 Å) (in pink color) make a trifurcated HB which leads toincreases of 0.046, 0.045 and 0.041 Å, respectively. Moreover,C10�H10���S2 (2.966 Å), N4�H4A���S2 (2.825 Å), and C11�H11���S2(3.027 Å) (in orange color) formed another trifurcated HB resultingin the bond lengthening of 0.069, 0.081, and 0.072 Å, respectively.Finally, N2�H2B���S2 (2.591 Å) and N2�H2B���C20 (2.898 Å) (in vio-let color) with the participating donor site (N2�H2B) make a bifur-cated HB that has a diminutive effect on each other therebyincreasing their length by 0.054 and 0.059 Å. All of these weakenedbonds destabilize 1-net by approximately 8.79 kJ mol�1. Our calcu-lated results for the binding and stabilization energies of the net-work show good agreement with the other reported results suchas QTAIM of Bader theory [29,30,39–41,52]. The conclusion shouldbe highlighted that unconventional N�H� � �S, N�H� � �C, C�H� � �S,and C�H� � �N govern the crystal packing formation and providemore than 75% of the1-net stabilization energy. The calculatedvalue of the involved non-covalent interactions can be ordered asN�H� � �S > N–H� � �C>C–H� � �N>C–H� � �S>C–H� � �p>p���p (see Table 5).

4. Conclusion

In this work, the new compound of infrequent Co(II) complexeswith 8-aq ligand (cis�[Co(8-aq)2(NCS)2]) (see SI) is reported and itsstructure was characterized by single crystal X–ray diffraction. Theoptimized DFT–D � B3LYP/6–311+G(d,p) structure of 1–net showsthat N–H� � �S, N–H� � �C, C–H� � �N, and C–H� � �S HBs and C�H� � �p, andp���p stacking contacts stabilize the crystalline 3D network. Thecomputed results show that HBs govern the formation of 1–netwith the following stabilization sequence of the involving interac-tions: N�H� � �S>N–H� � �C>C–H� � �N>C–H� � �S > C–H� � �p > p���p.

Acknowledgment

MM gratefully acknowledges the financial support by the Fer-dowsi University of Mashhad (Grant No. 3/23920). MCH gratefullyacknowledges the financial support by the Hakim SabzevariUniversity, Sabzevar, Iran. JTM gratefully acknowledges the sup-port of the National Science Foundation through NSF-MRI Grant#1228232 for the purchase of the D8 diffractometer and TulaneUniversity for support of the Tulane Crystallography Laboratory.

This research did not receive any specific grant from fundingagencies in the public, commercial, or not-for-profit sectors.

Z. Rahmati et al. / Inorganica Chimica Acta 473 (2018) 152–159 159

Appendix A. Supplementary data

Supplementary data associated with this article can be found, inthe online version, at https://doi.org/10.1016/j.ica.2017.12.033.

References

[1] D. Braga, F. Grepioni, A.G. Orpen, From molecules to crystals to materials,Crystal Engineering, Dordrecht, Kluwer, 1999.

[2] G.R. Desiraju, Structure and Function, Perspectives in SupramolecularChemistry, Crystal Engineering, Chichester, Wiley, 2003.

[3] E.R. Tiekink, J.J. Vittal, Frontiers in Crystal Engineering, Chichester, Wiley, 2005.[4] B. Moulton, M.J. Zaworotko, Chem. Rev. 101 (2001) 1629.[5] K. Tanaka, F. Toda, Chem. Rev. 100 (2000) 1025.[6] L. Carlucci, G. Ciani, D.M. Proserpio, Coord. Chem. Rev. 246 (2003) 247.[7] X.-M. Lin, L. Chen, H.-C. Fang, Z.-Y. Zhou, X.-X. Zhou, J.-Q. Chen, A.-W. Xu, Y.-P.

Cai, Inorg. Chim. Acta 362 (2009) 2619.[8] J. He, G.P. Tan, J.X. Zhang, Y.N. Zhang, Y.G. Yin, Inorg. Chem. Commun. 11

(2008) 1094.[9] A.D. Bond, What is a co-crystal?, CrystEngComm 9 (2007) 833[10] V.R. Hathwar, R. Pal, T. Guru Row, Cryst. Growth Des. 10 (2010) 3306.[11] M. Eftekhar, M. Mirzaei, A. Hassanpoor, I. Khosravi, A. Bauzá, J.T. Mague, A.

Frontera, J. Coord. Chem. 68 (2015) 3599.[12] H.N. Wang, J.S. Qin, D.Y. Du, G.J. Xu, X.L. Wang, K.Z. Shao, G. Yuan, L.J. Li, Z.M.

Su, Inorg. Chem. Commun. 13 (2010) 1227.[13] (a) T.L. Che, Q.C. Gao, W.P. Zhang, Z.X. Nan, H.X. Li, Y.G. Cai, J.S. Zhao, Russ. J.

Coord. Chem. 35 (2009) 723;(b) C. Adhikary, S. Koner, Coord. Chem. Rev. 254 (2010) 2933.

[14] H. Chun, J. Seo, Inorg. Chem. 48 (2009) 9980.[15] G. Yang, H.-G.B.-H. Zhu, X.-M.L. Chen, J. Chem. Soc. Dalton Trans. (2001) 580.[16] Z.-P. Deng, L.-H. Huo, M.-S. Li, L.-W. Zhang, Z.-B. Zhu, H. Zhao, S. Gao, Cryst.

Growth Des. 11 (2011) 3090.[17] J.D. van der Waals, Ph.D. thesis, University of Leiden, Leiden, The Netherlands,

1873.[18] G.R. Desiraju, T. Steiner, The Weak Hydrogen Bond in Structural Chemistry and

Biology, OUP, Oxford, 1999.[19] P. Metrangolo, H. Neukirch, T. Pilati, G. Resnati, Acc. Chem. Res. 38 (38) (2005)

386.[20] (a) T.T.T. Bui, S. Dahaoui, C. Lecomte, G.R. Desiraju, E. Espinosa, Angew. Chem.

Int. Ed. 48 (2009) 3838;(b) L. Brammer, G.M. Espallargas, S. Libri, CrystEngComm 10 (2008) 1712.

[21] (a) I. Omae, Chem. Rev. 79 (1979) 287;(b) A.Y. Robin, K.M. Fromm, Coord. Chem. Rev. 250 (2006) 2127.

[22] (a) B.L. Tekwami, L.A. Walker, Curr. Opin. Infect. Dis. 19 (2006) 623;(b) L. Morales, M.I. Toral, M.J.A. Ivarez, Talanta 74 (2007) 110.

[23] L. Yan, X. Wang, Y. Wang, Y. Zhang, Y. Liu, Z. Guo, J. Inorg. Biochem. 106 (2012)46.

[24] T. Yang, Ch. Tu, J. Zhang, L. Lin, X. Zhang, Q. Liu, J. Ding, Q. Xu, Z. Guo, DaltonTrans. (2003) 3419.

[25] K. Wang, M. Shena, W.-H. Sun, Dalton Trans. (2009) 4085.[26] M. Shen, W. Zhang, K. Nomurab, W.-H. Sun, Dalton Trans. 9000 (2009).

[27] K. Zelenka, H. Brandl, B. Spinglera, F. Zelder, Dalton Trans. 40 (2011) 9665.[28] A.M. Baruah, A. Karmakar, J.B. Baruah, Inorg. Chim. Acta 361 (2008) 2777.[29] M. Mirzaei, H. Eshtiagh-Hosseini, M. Mohammadi Abadeh, M. Chahkandi, A.

Frontera, A. Hassanpoor, CrystEngComm 15 (2013) 1404.[30] M. Mirzaei, H. Eshtiagh-Hosseini, Z. Bolouri, Z. Rahmati, A. Esmaeilzadeh, A.

Hassanpoor, A. Bauza, P. Ballester, M. Barceló-Oliver, J.T. Mague, B. Notash, A.Frontera, Cryst. Growth Des. 15 (2015) 1351.

[31] A. Panja, RSC Adv. 3 (2013) 4954.[32] (a) D.J. Harding, D. Sertphon, P. Harding, Acta Cryst. E68 (2012) m450;

(b) H. Xu, C. Guo, Acta Cryst. E68 (2012) m3;(c) A.M. Baruah, R. Sarma, J.B. Baruah, Inorg. Chem. Commun. 11 (2008) 121.

[33] (a) B. Krámos, A. Kovács, J. Mol. Struct. Theochem. 867 (1) (2008);(b) J. Chrappov, P. Schwendt, M. Sivk, M. Repiský, V.G. Malkin, J. Marek, DaltonTrans. (2009) 465.

[34] APEX2, SADABS, SAINT and SHELXTL,2012, Bruker-AXS, Madison, WI.[35] M.J. Frisch, G.W. Trucks, et al., GAUSSIAN09, revision A.02, Gaussian Inc.,

Wallingford, CT, 2009.[36] C. Lee, R.G. Parr, W. Yang, Phys. Rev. 37 (1988) B785.[37] A.D. Becke, J. Chem. Phys. 98 (1993) 5648.[38] A.D. Becke, Phys. Rev. A 38 (1988) 3098.[39] (a) M. Chahkandi, M.H. Bhatti, U. Yunus, S. Shaheen, M. Nadeem, M. Nawaz

Tahir, J. Mol. Struct. 1133 (2017) 499;(b) U. Yunus, S. Ahmed, M. Chahkandi, M.H. Bhatti, M. Nawaz Tahir, J. Mol.Struct. 1130 (2016) 688.

[40] (a) M. Mirzaei, H. Eshtiagh-Hosseini, M. Chahkandi, N. Alfi, A. Shokrollahi, N.Shokrollahi, A. Janiak, CrystEngComm 14 (2012) 8468;(b) H. Eshtiagh-Hosseini, M. Mirzaei, M. Biabani, V. Lippolis, M. Chahkandi, C.Bazzicalupi, CrystEngComm 15 (2013) 6752.

[41] (a) M. Chahkandi, J. Mol. Struct. 1111 (2016) 193;(b) H. Eshtiagh-Hosseini, M. Chahkandi, M.R. Housaindokht, M. Mirzaei,Polyhedron 60 (2013) 93.

[42] (a) J.E. Del Bene, W.B. Person, K. Szczepaniak, J. Phys. Chem. 99 (1995) 10705;(b) J. Florian, B.G. Johnson, J. Phys. Chem. 99 (1995) 5899;(c) J.E. Combarida, N.R. Kestner, J. Phys. Chem. 95 (1995) 2717;(d) C. Lee, C. Sosa, M. Planas, J.J. Novoa, J. Chem. Phys. 104 (1996) 7081.

[43] P. Jurecka, J. Cerny, P. Hobza, D.R. Salahub, J. Comput. Chem. 28 (2007) 555.[44] S.B. Boys, F. Bernardi, Mol. Phys. 19 (1970) 553.[45] C. Niu, X. Wan, X. Zheng, H. Zhang, B. Wu, Y. Niu, H. Hou, J. Coord. Chem. 61

(2008) 1997.[46] K.S. Min, T. Weyhermüller, K. Wieghardt, Dalton Trans. (2004) 178.[47] H. Xu, L.-F. Huang, X.-M. Ren, Chin. J. Inorg. Chem. 26 (2010) 171.[48] H. Xu, L.-F. Huang, L.-M. Guo, Y.-G. Zhang, X.-M. Ren, Y. Song, J. Xie, J. Lumin.

128 (2008) 1665.[49] C. Genre, E. Jeanneau, A. Bousseksou, D. Luneau, S.A. Borshch, G.S. Matouzenko,

Chem. Eur. J. 14 (2008) 697.[50] K.S. Seth, I. Saha, C. Estarellas, A. Frontera, T. Kar, S. Mukhopadhyay, Cryst.

Growth Des. 11 (2011) 3250.[51] (a) T.J. Mooibroek, P. Gamez, J. Reedijk, CrystEngComm 10 (2008) 1501;

(b) M. Egli, S. Sarkhel, Acc. Chem. Res. 40 (2007) 197.[52] (a) G.V. Baryshnikov, B.F. Minaev, V.A. Minaeva, V.G. Nenajdenko, J. Mol.

Model. 19 (2013) 4511;(b) B.F. Minaev, G.V. Baryshnikov, V.A. Minaeva, Dyes Pigm. 92 (2011) 531.

https://doi.org/10.1016/j.ica.2017.12.033http://refhub.elsevier.com/S0020-1693(17)31328-2/h0005http://refhub.elsevier.com/S0020-1693(17)31328-2/h0005http://refhub.elsevier.com/S0020-1693(17)31328-2/h0005http://refhub.elsevier.com/S0020-1693(17)31328-2/h0010http://refhub.elsevier.com/S0020-1693(17)31328-2/h0010http://refhub.elsevier.com/S0020-1693(17)31328-2/h0010http://refhub.elsevier.com/S0020-1693(17)31328-2/h0015http://refhub.elsevier.com/S0020-1693(17)31328-2/h0015http://refhub.elsevier.com/S0020-1693(17)31328-2/h0020http://refhub.elsevier.com/S0020-1693(17)31328-2/h0025http://refhub.elsevier.com/S0020-1693(17)31328-2/h0030http://refhub.elsevier.com/S0020-1693(17)31328-2/h0035http://refhub.elsevier.com/S0020-1693(17)31328-2/h0035http://refhub.elsevier.com/S0020-1693(17)31328-2/h0040http://refhub.elsevier.com/S0020-1693(17)31328-2/h0040http://refhub.elsevier.com/S0020-1693(17)31328-2/h0045http://refhub.elsevier.com/S0020-1693(17)31328-2/h0050http://refhub.elsevier.com/S0020-1693(17)31328-2/h0055http://refhub.elsevier.com/S0020-1693(17)31328-2/h0055http://refhub.elsevier.com/S0020-1693(17)31328-2/h0060http://refhub.elsevier.com/S0020-1693(17)31328-2/h0060http://refhub.elsevier.com/S0020-1693(17)31328-2/h0065http://refhub.elsevier.com/S0020-1693(17)31328-2/h0065http://refhub.elsevier.com/S0020-1693(17)31328-2/h0070http://refhub.elsevier.com/S0020-1693(17)31328-2/h0075http://refhub.elsevier.com/S0020-1693(17)31328-2/h0080http://refhub.elsevier.com/S0020-1693(17)31328-2/h0085http://refhub.elsevier.com/S0020-1693(17)31328-2/h0085http://refhub.elsevier.com/S0020-1693(17)31328-2/h0095http://refhub.elsevier.com/S0020-1693(17)31328-2/h0095http://refhub.elsevier.com/S0020-1693(17)31328-2/h0095http://refhub.elsevier.com/S0020-1693(17)31328-2/h0100http://refhub.elsevier.com/S0020-1693(17)31328-2/h0100http://refhub.elsevier.com/S0020-1693(17)31328-2/h0105http://refhub.elsevier.com/S0020-1693(17)31328-2/h0105http://refhub.elsevier.com/S0020-1693(17)31328-2/h0110http://refhub.elsevier.com/S0020-1693(17)31328-2/h0115http://refhub.elsevier.com/S0020-1693(17)31328-2/h0120http://refhub.elsevier.com/S0020-1693(17)31328-2/h0125http://refhub.elsevier.com/S0020-1693(17)31328-2/h0130http://refhub.elsevier.com/S0020-1693(17)31328-2/h0135http://refhub.elsevier.com/S0020-1693(17)31328-2/h0135http://refhub.elsevier.com/S0020-1693(17)31328-2/h0140http://refhub.elsevier.com/S0020-1693(17)31328-2/h0140http://refhub.elsevier.com/S0020-1693(17)31328-2/h0145http://refhub.elsevier.com/S0020-1693(17)31328-2/h0150http://refhub.elsevier.com/S0020-1693(17)31328-2/h0155http://refhub.elsevier.com/S0020-1693(17)31328-2/h0160http://refhub.elsevier.com/S0020-1693(17)31328-2/h0165http://refhub.elsevier.com/S0020-1693(17)31328-2/h0165http://refhub.elsevier.com/S0020-1693(17)31328-2/h0170http://refhub.elsevier.com/S0020-1693(17)31328-2/h0170http://refhub.elsevier.com/S0020-1693(17)31328-2/h0170http://refhub.elsevier.com/S0020-1693(17)31328-2/h0175http://refhub.elsevier.com/S0020-1693(17)31328-2/h0180http://refhub.elsevier.com/S0020-1693(17)31328-2/h0185http://refhub.elsevier.com/S0020-1693(17)31328-2/h0190http://refhub.elsevier.com/S0020-1693(17)31328-2/h0195http://refhub.elsevier.com/S0020-1693(17)31328-2/h0200http://refhub.elsevier.com/S0020-1693(17)31328-2/h0200http://refhub.elsevier.com/S0020-1693(17)31328-2/h0210http://refhub.elsevier.com/S0020-1693(17)31328-2/h0210http://refhub.elsevier.com/S0020-1693(17)31328-2/h0210http://refhub.elsevier.com/S0020-1693(17)31328-2/h0215http://refhub.elsevier.com/S0020-1693(17)31328-2/h0220http://refhub.elsevier.com/S0020-1693(17)31328-2/h0225http://refhub.elsevier.com/S0020-1693(17)31328-2/h0230http://refhub.elsevier.com/S0020-1693(17)31328-2/h0230http://refhub.elsevier.com/S0020-1693(17)31328-2/h0235http://refhub.elsevier.com/S0020-1693(17)31328-2/h0235http://refhub.elsevier.com/S0020-1693(17)31328-2/h0240http://refhub.elsevier.com/S0020-1693(17)31328-2/h0240http://refhub.elsevier.com/S0020-1693(17)31328-2/h0245http://refhub.elsevier.com/S0020-1693(17)31328-2/h0245http://refhub.elsevier.com/S0020-1693(17)31328-2/h0250http://refhub.elsevier.com/S0020-1693(17)31328-2/h0255http://refhub.elsevier.com/S0020-1693(17)31328-2/h0255http://refhub.elsevier.com/S0020-1693(17)31328-2/h0260http://refhub.elsevier.com/S0020-1693(17)31328-2/h0265http://refhub.elsevier.com/S0020-1693(17)31328-2/h0270http://refhub.elsevier.com/S0020-1693(17)31328-2/h0275http://refhub.elsevier.com/S0020-1693(17)31328-2/h0280http://refhub.elsevier.com/S0020-1693(17)31328-2/h0285http://refhub.elsevier.com/S0020-1693(17)31328-2/h0290http://refhub.elsevier.com/S0020-1693(17)31328-2/h0290http://refhub.elsevier.com/S0020-1693(17)31328-2/h0295http://refhub.elsevier.com/S0020-1693(17)31328-2/h0300http://refhub.elsevier.com/S0020-1693(17)31328-2/h0305http://refhub.elsevier.com/S0020-1693(17)31328-2/h0305http://refhub.elsevier.com/S0020-1693(17)31328-2/h0310http://refhub.elsevier.com/S0020-1693(17)31328-2/h0310http://refhub.elsevier.com/S0020-1693(17)31328-2/h0315http://refhub.elsevier.com/S0020-1693(17)31328-2/h0315http://refhub.elsevier.com/S0020-1693(17)31328-2/h0320http://refhub.elsevier.com/S0020-1693(17)31328-2/h0325http://refhub.elsevier.com/S0020-1693(17)31328-2/h0330http://refhub.elsevier.com/S0020-1693(17)31328-2/h0330http://refhub.elsevier.com/S0020-1693(17)31328-2/h0335

Accurate DFT studies on crystalline network formation of a new Co(II) complex bearing 8-aminoquinoline1 Introduction2 Experimental2.1 Materials and measurements2.2 Synthesis of [Co(8-aq)2(NCS)2]2.3 Structure determination2.4 Computational details

3 Results and discussion3.1 Synthesis3.2 Experimental and theoretical crystal description of 13.3 Crystal packing constructed by Non-covalent interactions: Theoretical consideration

4 ConclusionAcknowledgmentAppendix A Supplementary dataReferences