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Crystal Growth, Characterization, and Properties of Reduced Early Transition Metal Compounds Grown via Hydrothermal and Molten Salt Flux Methods Anthony J. D. Cortese, Branford Wilkins, Gregory Morrison, Jeongho Yeon, Mark D. Smith, Hans-Conrads zur Loye Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 Abstract Conclusions Acknowledgments Nd 4.910 Mo 3 O 16 & Sm 4.952 Mo 3 O 16 La 20 Mo 12 O 63 Cl 4 Ba 3 Na 0.32 Nb 6 O 12 (Si 2 O 7 ) 2 Ln 5 Mo 2 O 12 Ln = Tb, Dy, Ho, Er Na x Ln 1-x MoO 4 Ln = La, Nd, Sm, Eu A 2 [(VO) 2 (C 4 H 4 O 6 )(C 4 H 2 O 6 )(H 2 O) 2 ]•(H 2 O) 2 A = Cs, Rb; 1, 2 K 2 [(VO) 2 (C 4 H 2 O 6 ) 2 (H 2 O) 2 ]•(H 2 O) 2 ; 3 Na 2 [(VO) 2 (C 4 H 4 O 6 )(C 4 H 2 O 6 )(H 2 O) 7 ]•(H 2 O) 2 ; 4 Research was supported by the U.S. Department of Energy, Office of Basic Energy Studies, Materials Sciences and Engineering Division under DE- SC-0001061 and the National Science Foundation under DMR-1301757. SHG measurements were performed at the University of Houston by T. Thao Tran of the P. Shiv Halasyamani Group, and are gratefully acknowledged. Four oxovanadium(IV) tartrates, four sodium lanthanide molybdenum(V/VI) oxides, four lanthanide molybdenum(IV/V) oxides, one lanthanum molybdenum(V/VI) oxychloride, one barium sodium siliconiobate(IV/V), and two lanthanide molybdenum(V/VI) oxides have been synthesized via a novel two step reduction technique and high temperature flux methods. Their crystal structures were determined by single crystal X-ray diffraction. Magnetic properties and absorbance have been determined via SQUID-VSM and UV/Vis, respectively. Several compounds exhibit magnetic ordering. Several compounds have absorption edges that fall in the visible region, indicating semiconducting behavior. Conductivity measurements are underway. SHG properties have been investigated for applicable compounds, with several having comparable activity to a known standard. A limited number of compounds containing reduced early transition metals are known due to the difficulty of their preparation. Four vanadium tartrate hybrid materials, A 2 [(VO) 2 (C 4 H 4 O 6 )(C 4 H 2 O 6 )(H 2 O) 2 ](H 2 O) 2 A = Cs, Rb; K 2 [(VO) 2 (C 4 H 2 O 6 ) 2 (H 2 O) 2 ](H 2 O) 2 ; and Na 2 [(VO) 2 (C 4 H 4 O 6 )(C 4 H 2 O 6 )(H 2 O) 7 ](H 2 O) 2 , were prepared via a novel two step hydrothermal technique. Six lanthanide molybdenum oxides, Ln 5 Mo 2 O 12 Ln = Tb, Dy, Ho and Er, Ln ~5 Mo 3 O 16 Ln = Nd, Sm; four new sodium lanthanide molybdenum oxides, Na x Ln 1-x MoO 4 Ln = La, Nd, Sm, and Eu; a lanthanum molybdenum oxychloride, La 20 Mo 12 O 63 Cl 4 ; and a barium sodium siliconiobate, Ba 3 Na 0.32 Nb 6 Si 4 O 26 were prepared via high temperature flux methods in sealed evacuated fused silica tubes. These materials have been characterized via powder and single crystal X-ray diffraction, UV/Vis spectroscopy, and IR spectroscopy. Magnetism has been probed using a SQUID/ VSM magnetometer. Second harmonic generation has been investigated for A 2 [(VO) 2 (C 4 H 4 O 6 )(C 4 H 2 O 6 )(H 2 O) 2 ](H 2 O) 2 A = Cs, Rb, K 2 [(VO) 2 (C 4 H 2 O 6 ) 2 (H 2 O) 2 ] (H 2 O) 2 , La 20 Mo 12 O 63 Cl 4 , and Ba 3 Na 0.32 Nb 6 Si 4 O 26 . Figure 1. 1 and 2 viewed down the a axis. V, A, O, C, H shown in blue, yellow, red, grey, and white. Hydrogen bonds shown as red/white stripped cylinders. Figure 2. 4 viewed down the a axis. V, Na, O, C, H shown in blue, yellow, red, grey, and white. Hydrogen bonds shown as red/white stripped cylinders. Figure 5. 3 viewed in the bc plane. V, K, O, C, H shown in blue, yellow, red, grey, and white. Figure 3. V 2 O 12 dimer of 1 and 2. The dimer of 4 is similar. V, O, C, H shown in blue, red, grey, and white. Hydrogen bond shown as a red/white stripped cylinder. Figure 4. V 2 O 9 dimer of 3. V, O, C, H shown in blue, red, grey, and white. Figure 6. 3 viewed in the ab plane. V, K, O, C, H shown in blue, yellow, red, grey, and white. Figure 7. Calculated (red) and experimental (blue) PXRD patterns for 1, 2, 3, and 4. Figure 8. Temperature dependance of the molar magnetic susceptibility (blue), χ m , and inverse susceptibility (red), 1/χ m , of 1, 2, and 4. Temperature dependance of the molar magnetic susceptibility (red), χ m , and fit (blue) of 3. Figure 9. Powder SHG data of 1, 2, and 3 relative to α-SiO 2 . Absorbance data for 1 (red), 2 (green), 3(blue), and 4 (black). A = Cs S.G. P2 1 2 1 2 1 a/Å 8.0320(6) b/Å 10.4016(8) c/Å 23.3623(17) Z 4 R1 0.0210 wR2 0.0487 A = Rb S.G. P2 1 2 1 2 1 a/Å 7.9061(8) b/Å 10.2647(11) c/Å 22.814(2) Z 4 R1 0.0238 wR2 0.0543 A = K S.G. C222 1 a/Å 8.4341(13) b/Å 17.311(3) c/Å 25.140(4) Z 4 R1 0.0339 wR2 0.0616 A = Na S.G. P2 1 2 1 2 1 a/Å 8.5931(5) b/Å 10.4332(6) c/Å 24.2289(13) Z 4 R1 0.0398 wR2 0.0877 Ln = Ho S.G. C2/m a/Å 12.2959(14) b/Å 5.7377(7) c/Å 7.5300(9) β/° 107.816(2) Z 2 R1 0.0423 wR2 0.0852 Ba 3 Na 0.32 Nb 6 O 12 (Si 2 O 7 ) 2 S.G. P-62m a/Å 8.9998(10) b/Å 8.9998(10) c/Å 7.8119(17) Z 1 R1 0.0189 wR2 0.0381 Ln = Er S.G. C2/m a/Å 12.1871(18) b/Å 5.7044(8) c/Å 7.4581(11) β/° 107.884(3) Z 2 R1 0.0367 wR2 0.0877 Figure 3. MoO 6 1D chains showing alternating Mo - Mo distances. Mo and O shown in cyan and red. Figure 4. Calculated (red) and experimental (blue) PXRD patterns for Er (left) and Ho (right). Figure 5. Temperature dependance of the molar magnetic susceptibility (blue), χ m , and inverse susceptibility (red), 1/χ m , of Er (left) and Ho (right). Figure 1. Ln 5 Mo 2 O 12 viewed down the c axis. Ln, Mo, and O shown in orange, cyan, and red. Figure 2. Local coordination environments of Ln 5 Mo 2 O 12. Ln, Mo, and O shown in orange, cyan, and red. Figure 2. Local coordination environments of Ba 3 Na 0.32 Nb 6 O 12 (Si 2 O 7 ) 2. Ba, Na, Nb, Si, and O shown in pink, yellow, cyan, blue, and red. Figure 1. Ba 3 Na 0.32 Nb 6 O 12 (Si 2 O 7 ) 2 viewed down the c axis. Ba, Na, Nb, Si, and in pink, yellow, cyan, and blue. Na shown at full occupancy for clarity. Figure 3. Nb 3 O 15 trimeric columns. Nb and O shown in cyan and red. Figure 4. Calculated (red) and experimental (blue) PXRD patterns for Ba 3 Na 0.32 Nb 6 O 12 (Si 2 O 7 ) 2 . Figure 7. IR spectrum for Ba 3 Na 0.32 Nb 6 O 12 (Si 2 O 7 ) 2 . Figure 6. UV/Vis spectrum for Ba 3 Na 0.32 Nb 6 O 12 (Si 2 O 7 ) 2 . Figure 5. Temperature dependance of the molar magnetic susceptibility (blue), χ m , and inverse susceptibility (red), 1/ χ m , of Ba 3 Na 0.32 Nb 6 O 12 (Si 2 O 7 ) 2 .. Figure 6. Absorbance data for Tb (black), Dy (red), Ho (blue), and Er (green). Ln = La S.G. I4 1 /a a/Å 5.3414(2) c/Å 11.7393(6) Z 4 R1 0.0271 wR2 0.0434 Figure 2. Calculated (red) and experimental (blue) PXRD patterns for La (top left), Nd (top right), Sm (bottom left), and Eu (bottom right). Ln = Nd S.G. I4 1 /a a/Å 5.2854(2) c/Å 11.5675(6) Z 4 R1 0.0185 wR2 0.0474 Ln = Sm S.G. I4 1 /a a/Å 5.2560(2) c/Å 11.4921(2) Z 4 R1 0.0252 wR2 0.0664 Ln = Eu S.G. I4 1 /a a/Å 5.2797(2) c/Å 11.5869(7) Z 4 R1 0.0161 wR2 0.0334 Figure 4. Temperature dependance of the molar magnetic susceptibility (blue), χ m , and inverse susceptibility (red), 1/χ m , of Na 0.6 Eu 0.4 MoO 4 . Figure 1. Na x Ln 1-x MoO 4 viewed down the a axis. Na/Ln, Mo, and O shown in orange, cyan, and red. La 20 Mo 12 O 63 Cl 4 S.G. P-62m a/Å 10.2241(2) b/Å 10.2241(2) c/Å 15.0768(4) Z 1 R1 0.0254 wR2 0.0494 Ln = Nd S.G. Pn-3n a/Å 10.9959(7) Z 4 R1 0.0205 wR2 0.0383 Ln = Sm S.G. Pn-3n a/Å 10.8934(4) Z 4 R1 0.0202 wR2 0.0435 Figure 5. Calculated (red) and experimental (blue) PXRD patterns for La 20 Mo 12 O 63 Cl 4 Figure 2 (at right). Mo1/ La1/La2/La3 oxychloride layer viewed down the c axis. La2 and La3 are located on top of one another in the c direction and connect to Mo3 and Mo2 layers, respectively. Cl1 and Cl2 are located on top of one another in the c direction. Figure 3 (at left). Mo2/ La3/La4 oxychloride layer viewed down the c axis. Two La3 are located on top of one another in the c direction and connect to Mo1 layers. Cl2 and Cl1 are located on top of one another in the c direction. Figure 4 (above). Mo3/La2/La5 oxide layer viewed down the c axis. Two La2 are located on top of one another in the c direction and connect to Mo1 layers. Figure 6. Absorbance data for La 20 Mo 12 O 63 Cl 4 . Figure 1. La 20 Mo 12 O 63 Cl 4 viewed down the a axis. Mo1, Mo2, Mo3, La, and Cl shown in aqua, cyan, navy, orange, and green. Some La-O bonds omitted for clarity. Molybdenum layers stack in A, B, A, C fashion. Figure 3. Absorbance data for La (blue), Nd (black), Sm (red), and Eu (green). Figure 6. Temperature dependance of the molar magnetic susceptibility (blue), χ m , and inverse susceptibility (red), 1/χ m , of Nd. Figure 5. Absorbance data for Nd. Figure 4. Calculated (red) and experimental (blue) PXRD patterns for Nd. Figure1. Local coordination environments of Ln~ 5 Mo 3 O 16. Ln1, Ln2, Mo, and O shown in orange, purple, cyan, and red. Figure 2. Local coordination environments of Ln~ 5 Mo 3 O 16. Ln1, Ln2, Mo, and O shown in orange, purple, cyan, and red. Figure 3. Ln ~5 Mo 3 O 16 viewed down the a axis. Ln1, Ln2, Mo, and O shown in orange, purple , cyan, and red. Ln2 - Mo bonds not shown for clarity.
