V(acetonitrile)4Br2 | 168100-78-5

• 英文名称: V(acetonitrile)4Br2
• CAS: 168100-78-5
• 化学式: C₈H₁₂Br₂N₄V
• 分子量: 374.96
• InChiKey: DYZFPCGCHSBPHT-UHFFFAOYSA-L

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
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• 可旋转键数：
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• 环数：
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• sp3杂化的碳原子比例：
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• 拓扑面积：
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• 氢给体数：
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• 氢受体数：
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反应信息

• 作为产物：
  描述：

  [V(acetonitrile)6](O3SCF3)2 * 0.5 MeCN 、 lithium bromide 以 乙腈 为溶剂， 以65%的产率得到V(acetonitrile)4Br2
  参考文献：
  名称：

  Vanadium(II) Salts in Pyridine and Acetonitrile Solvents

  摘要：

  Earlier work on the interaction of V(II ) salts with pyridine and acetonitrile as solvents has been extended. The structure of the compound VPy(4)(O3SCF3)(2), 1, an intermediate in many of the preparations, has been determined by X-ray diffraction. Analogous solids with I-, Br-, Cl-, SCN-, N-3(-), PhS(-), EtS(-), and BH4- as counterions have been prepared. Attempts to prepare solids with PhO(-), HO-, MeO(-), Ph(-), CN-, AlH4-, and H- failed, but the tetrapyridine complexes were prepared by titrating a solution of 1 in pyridine with the lithium salt of each anion (in the case of H-, the anion was Et(3)BH(-)) to an end point observed at the 1:2 ratio. Comparisons in a number of cases of the absorption spectra and of the cyclovoltammetric behavior of the tetrapyridine salts in pyridine and in CH2Cl2 show the species in the two solvents to be the same and to correspond to the composition of the solids. Intercomparisons of the absorption spectra in pyridine suggest that the complexes with the aforementioned anions all have similar structures: four pyridine molecules situated equatorially-on the basis of crystal structure determinations, in a propeller arrangement--and the anions occupying axial positions. The initial absorption spectrum of a solution of VPy(4)(PF6)(2) in pyridine changes to that shown by a solution of VPy(6)(PF6)(2) or of VPy(6)(BPh(4))(2), and we conclude that with these weakly nucleophilic anions VPy(6)(2+) is the dominant form of V(II) in pyridine solution. In every case, the prominent feature of the absorption spectrum is a band envelope consisting of a maximum that ranges from 586 to 400 nm accompanied by a shoulder which usually lies on ther low-energy side of the dominant peak and which in these cases we assign to nu(CT) and nu(1)'', respectively. The latter is the higher energy component of the two transitions nu(1)' and nu(1)'', which arise from nu(1) (octahedral) when the symmetry is reduced to axial. Energy correlations suggest that nu(CT) always lies at higher energy than nu(1)'', so that when the shoulder lies on the high-energy side of the dominant peak, epsilon(nu(1)'') exceeds epsilon(nu(CT)) In a number of cases nu(1)' is observed. It is of much lower intensity than nu(1)'', and the wavelengths of the transitions lie in the range of 600 nm and higher and vary with the nature of ligands as observed in other cases of axial symmetry. The absorption characteristics of Vqy(6)(2+) resemble those of the tetrapyridine complexes, suggesting that the propellerlike arrangement is retained in this species, two pyridines replacing the anions in the axial positions; i.e., the axial and equatorial pyridines are inequivalent.

  DOI：

  10.1021/ic00127a013