This paper reports the features and regularities of the infrared spectra for two kinds of complexes containing R 2dtc ligand. The cubane like clusters containing R 2dtc ligand possess weak and wide peaks at 400—500 c...This paper reports the features and regularities of the infrared spectra for two kinds of complexes containing R 2dtc ligand. The cubane like clusters containing R 2dtc ligand possess weak and wide peaks at 400—500 cm -1 assigned to M μ 3S vibration,while the peaks at 330—380 cm -1 and 1 470—1 510 cm -1 can be assigned to M S dtc and C—N vibrations,respectively.The ν ( C—N ) and ν (C=S) vibrations for Me 2dtc cubane cluster exhibit blue shift and red shift,respectively,when compared with those of other R 2dtc ones.This would be attributed to the strong super conjugation of the methly group. The M μ 3S vibrations for both types of complexes [V 2Cu 2S 4(R 2dtc) 2(PhS) 2] 2- and [VCu 4S 4(R 2dtc) n(PhS) 4-n ] 3- ( n =0,1,2) occur at 480 and 465 cm -1 ,respectively.This small difference becomes a useful indication to distinguish the two types of clusters. Cluster complexes containing (R 2dtc) 2V 2O 2(μ S) 2 structural unit show the V=O vibration in the range of 844—970 cm -1 .It is noted that (Et 4N)[V 3S 2O 3(Et 2dtc) 3] contains two sets of the V=O bonds corresponding to two sets of V=O vibrations at 970 and 844 cm -1 .An additional coordination of the V=O bond to another metal atom obviously weakens the V=O bond to give rise to the red shift of the infrared frequency.Similar red shifts were also observed for other complexes and were discussed.展开更多
文摘This paper reports the features and regularities of the infrared spectra for two kinds of complexes containing R 2dtc ligand. The cubane like clusters containing R 2dtc ligand possess weak and wide peaks at 400—500 cm -1 assigned to M μ 3S vibration,while the peaks at 330—380 cm -1 and 1 470—1 510 cm -1 can be assigned to M S dtc and C—N vibrations,respectively.The ν ( C—N ) and ν (C=S) vibrations for Me 2dtc cubane cluster exhibit blue shift and red shift,respectively,when compared with those of other R 2dtc ones.This would be attributed to the strong super conjugation of the methly group. The M μ 3S vibrations for both types of complexes [V 2Cu 2S 4(R 2dtc) 2(PhS) 2] 2- and [VCu 4S 4(R 2dtc) n(PhS) 4-n ] 3- ( n =0,1,2) occur at 480 and 465 cm -1 ,respectively.This small difference becomes a useful indication to distinguish the two types of clusters. Cluster complexes containing (R 2dtc) 2V 2O 2(μ S) 2 structural unit show the V=O vibration in the range of 844—970 cm -1 .It is noted that (Et 4N)[V 3S 2O 3(Et 2dtc) 3] contains two sets of the V=O bonds corresponding to two sets of V=O vibrations at 970 and 844 cm -1 .An additional coordination of the V=O bond to another metal atom obviously weakens the V=O bond to give rise to the red shift of the infrared frequency.Similar red shifts were also observed for other complexes and were discussed.
