TY - JOUR
T1 - Vanadium, molybdenum, and sodium triethanolamine complexes derived from an assembly system containing tetrathiometalate and triethanolamine
AU - Chen, Y.
AU - Liu, Q.
AU - Deng, Y.
AU - Zhu, H.
AU - Chen, C.
AU - Fan, H.
AU - Liao, D.
AU - Gao, E.
PY - 2001/7/16
Y1 - 2001/7/16
N2 - 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 {MCV6O6 [N(CH2-CH2O)2 (CH2CH2OH)]6}2S6 (M = Na (1), Li (2)) contain two cyclic V(IV) [12]metallacrown-6 cations linked by a 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-D network structure. Variable-temperature conductance of 3 was determined to display semiconductor feature. The desulfurization 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(μ-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-dimensional structures for all these complexes by the linkages between clusters and chains. The IR spectrum indicates the structural similarity of complexes 1 and 2. For complex 4, the Mo=S stretch vibration at 468 cm-1 showing widening and slight red-shift and the slight movement of the 1H NMR signals of TEA ligand to downfield are considered to be the influence of the S···H-O hydrogen bonds. Variable temperature magnetic susceptibility data were collected for complex 1. The effect magnetic moment per V6 unit varies gradually from 4.04 μB at 300 K to 6.24 μB at 5 K, exhibiting ferromagnetic interaction. Heisenberg-type vector-coupling model and molecular field approximation were used to treat the interaction between the paramagnetic sites and gave a good fitting result: J = 3.97 cm-1, J′ = 1.99 cm-1, g = 1.99, F = 3.64 × 10-3. Density functional calculation was also performed to complex 1 and its Li, K analogues. The lowest total bonding energy of -874.001 eV was obtained for [Na⊂V6(μ3-O)6] complex containing six unpaired electrons, indicating the stability of a V6 system with six independent spins S = 1/2. When the alkali metal ion is inserted into the [V6(μ3-O)6] cavity, the positive values of the bonding interaction (Eb) indicate that the insertion depresses the total energy and that complexes 1 and 2 together with K+ complex may exist. However, the lowest Eb value of the K+ complex implies its instability.
AB - 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 {MCV6O6 [N(CH2-CH2O)2 (CH2CH2OH)]6}2S6 (M = Na (1), Li (2)) contain two cyclic V(IV) [12]metallacrown-6 cations linked by a 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-D network structure. Variable-temperature conductance of 3 was determined to display semiconductor feature. The desulfurization 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(μ-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-dimensional structures for all these complexes by the linkages between clusters and chains. The IR spectrum indicates the structural similarity of complexes 1 and 2. For complex 4, the Mo=S stretch vibration at 468 cm-1 showing widening and slight red-shift and the slight movement of the 1H NMR signals of TEA ligand to downfield are considered to be the influence of the S···H-O hydrogen bonds. Variable temperature magnetic susceptibility data were collected for complex 1. The effect magnetic moment per V6 unit varies gradually from 4.04 μB at 300 K to 6.24 μB at 5 K, exhibiting ferromagnetic interaction. Heisenberg-type vector-coupling model and molecular field approximation were used to treat the interaction between the paramagnetic sites and gave a good fitting result: J = 3.97 cm-1, J′ = 1.99 cm-1, g = 1.99, F = 3.64 × 10-3. Density functional calculation was also performed to complex 1 and its Li, K analogues. The lowest total bonding energy of -874.001 eV was obtained for [Na⊂V6(μ3-O)6] complex containing six unpaired electrons, indicating the stability of a V6 system with six independent spins S = 1/2. When the alkali metal ion is inserted into the [V6(μ3-O)6] cavity, the positive values of the bonding interaction (Eb) indicate that the insertion depresses the total energy and that complexes 1 and 2 together with K+ complex may exist. However, the lowest Eb value of the K+ complex implies its instability.
UR - https://www.scopus.com/pages/publications/0035898088
U2 - 10.1021/ic010126c
DO - 10.1021/ic010126c
M3 - 文章
C2 - 11442370
AN - SCOPUS:0035898088
SN - 0020-1669
VL - 40
SP - 3725
EP - 3733
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 15
ER -