Vanadium, Molybdenum, and Sodium Triethanolamine Complexes Derived from an Assembly System Containing Tetrathiometalate and Triethanolamine
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- 作者：Yihui Chen ; Qiutian Liu ; Yuheng Deng ; Hongping Zhu ; Changneng Chen ; Hongjun Fan ; Daizheng Liao ; and Enqing Gao
- 刊名：Inorganic Chemistry
- 出版年：2001
- 出版时间：July 16, 2001
- 年：2001
- 卷：40
- 期：15
- 页码：3725 - 3733
- 全文大小：172K
- 年卷期：v.40,no.15(July 16, 2001)
- ISSN：1520-510X
文摘
The reaction system composed of triethanolamine (TEA) and tetrathiovanadate in the presence of MeONa (MeOLi)or NaNH2 was studied to afford vanadium and alkali metal TEA complexes. Complexes {M
V6O6[N(CH2CH2O)2(CH2CH2OH)]6}2S6 (M = Na (1), Li (2)) contain two cyclic V(IV) [12]metallacrown-6 cations linked bya polysulfide S62- anion. Also separated from the reaction system is a novel sodium TEA complex {[Na(TEA)]2S6}n(3), in which parallel coordination chains [Na(TEA)+]n are connected by O-H···S hydrogen bonds forming 3-Dnetwork structure. Variable-temperature conductance of 3 was determined to display semiconductor feature. Thedesulfurization of VS43- was observed to form S62- anion and/or S8 molecule in the synthetic reactions of 1-3.A striking contrast was noted that MoS42- did not desulfurize in the similar reaction to that of VS43- with TEA,and a Na/TEA complex containing MoS42-, (Et4N)2[Na2(
-TEA)2(CH3OH)2](MoS4)2 (4), was obtained instead.The S···H-O and O···H-O hydrogen bonds play an important role in forming the one- or three-dimensionalstructures for all these complexes by the linkages between clusters and chains. The IR spectrum indicates thestructural similarity of complexes 1 and 2. For complex 4, the Mo=S stretch vibration at 468 cm-1 showingwidening and slight red-shift and the slight movement of the 1H NMR signals of TEA ligand to downfield areconsidered to be the influence of the S···H-O hydrogen bonds. Variable temperature magnetic susceptibilitydata were collected for complex 1. The effect magnetic moment per V6 unit varies gradually from 4.04 B at 300K to 6.24 B at 5 K, exhibiting ferromagnetic interaction. Heisenberg-type vector-coupling model and molecularfield approximation were used to treat the interaction between the paramagnetic sites and gave a good fittingresult: J = 3.97 cm-1, J' = 1.99 cm-1, g = 1.99, F = 3.64 × 10-3. Density functional calculation was alsoperformed to complex 1 and its Li, K analogues. The lowest total bonding energy of -874.001 eV was obtainedfor [NaV6(3-O)6] complex containing six unpaired electrons, indicating the stability of a V6 system with sixindependent spins S = 1/2. When the alkali metal ion is inserted into the [V6(3-O)6] cavity, the positive valuesof the bonding interaction (Eb) indicate that the insertion depresses the total energy and that complexes 1 and 2together with K+ complex may exist. However, the lowest Eb value of the K+ complex implies its instability.
V6O6[N(CH2CH2O)2(CH2CH2OH)]6}2S6 (M = Na (1), Li (2)) contain two cyclic V(IV) [12]metallacrown-6 cations linked bya polysulfide S62- anion. Also separated from the reaction system is a novel sodium TEA complex {[Na(TEA)]2S6}n(3), in which parallel coordination chains [Na(TEA)+]n are connected by O-H···S hydrogen bonds forming 3-Dnetwork structure. Variable-temperature conductance of 3 was determined to display semiconductor feature. Thedesulfurization of VS43- was observed to form S62- anion and/or S8 molecule in the synthetic reactions of 1-3.A striking contrast was noted that MoS42- did not desulfurize in the similar reaction to that of VS43- with TEA,and a Na/TEA complex containing MoS42-, (Et4N)2[Na2(-TEA)2(CH3OH)2](MoS4)2 (4), was obtained instead.The S···H-O and O···H-O hydrogen bonds play an important role in forming the one- or three-dimensionalstructures for all these complexes by the linkages between clusters and chains. The IR spectrum indicates thestructural similarity of complexes 1 and 2. For complex 4, the Mo=S stretch vibration at 468 cm-1 showingwidening and slight red-shift and the slight movement of the 1H NMR signals of TEA ligand to downfield areconsidered to be the influence of the S···H-O hydrogen bonds. Variable temperature magnetic susceptibilitydata were collected for complex 1. The effect magnetic moment per V6 unit varies gradually from 4.04 B at 300K to 6.24 B at 5 K, exhibiting ferromagnetic interaction. Heisenberg-type vector-coupling model and molecularfield approximation were used to treat the interaction between the paramagnetic sites and gave a good fittingresult: J = 3.97 cm-1, J' = 1.99 cm-1, g = 1.99, F = 3.64 × 10-3. Density functional calculation was alsoperformed to complex 1 and its Li, K analogues. The lowest total bonding energy of -874.001 eV was obtainedfor [NaV6(3-O)6] complex containing six unpaired electrons, indicating the stability of a V6 system with sixindependent spins S = 1/2. When the alkali metal ion is inserted into the [V6(3-O)6] cavity, the positive valuesof the bonding interaction (Eb) indicate that the insertion depresses the total energy and that complexes 1 and 2together with K+ complex may exist. However, the lowest Eb value of the K+ complex implies its instability.© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |