Lassen Peter R, Guy Laure, Karame Iyad, Roisnel Thierry, Vanthuyne Nicolas, Roussel Christian, Cao Xiaolin, Lombardi Rosina, Crassous Jeanne, Freedman Teresa B, Nafie Laurence A
Department of Chemistry, Syracuse University, Syracuse, New York 13244, USA.
Inorg Chem. 2006 Dec 11;45(25):10230-9. doi: 10.1021/ic061418m.
The infrared and vibrational circular dichroism (VCD) spectra of six chiral oxorhenium(V) complexes, bearing a hydrotris(1-pyrazolyl)borate (Tp) ligand, have been investigated. These complexes are promising candidates for observation of parity violation (symmetry breaking due to the weak nuclear force). New chiral oxorhenium complexes have been synthesized, namely, [TpReO(eta2-O(CH3)CH2CH2O-O,O)] (4a and 4b) diastereomers and [TpReO(eta2-N(CH3)CH2CH2O-N,O)] (5) and [TpReO(eta2-N(tBu)CH2CH2O-N,O)] (6) enantiomers. All compounds could be obtained in enantiomerically pure form by using either column chromatography or HPLC over chiral columns. VCD spectroscopy of these compounds and of [TpReO(eta2-N(CH3)CH(CH3)CH(Ph)O-N,O)] (2) and [TpReO(eta2-N(CH2)3CHCO2-N,O)] (3) (with chiral bidentate ligands derived, respectively, from ephedrine and proline) were studied. This allowed the absolute configuration determination of all compounds together with their conformational analysis, by comparing calculated and experimental spectra. This is the first VCD study of rhenium complexes which further demonstrates the applicability of VCD spectroscopy in determining the chirality of inorganic complexes.
对六种带有氢三（1 - 吡唑基）硼酸酯（Tp）配体的手性氧铼（V）配合物的红外光谱和振动圆二色性（VCD）光谱进行了研究。这些配合物是观察宇称破坏（由于弱核力导致的对称性破缺）的有前途的候选物。合成了新的手性氧铼配合物，即非对映异构体[TpReO(η² - O(CH₃)CH₂CH₂O - O,O)]（4a和4b）以及对映异构体[TpReO(η² - N(CH₃)CH₂CH₂O - N,O)]（5）和[TpReO(η² - N(tBu)CH₂CH₂O - N,O)]（6）。所有化合物都可以通过使用柱色谱法或在手性柱上进行高效液相色谱法以对映体纯形式获得。研究了这些化合物以及[TpReO(η² - N(CH₃)CH(CH₃)CH(Ph)O - N,O)]（2）和[TpReO(η² - N(CH₂)₃CHCO₂ - N,O)]（3）（分别衍生自麻黄碱和脯氨酸的手性双齿配体）的VCD光谱。通过比较计算光谱和实验光谱，这使得能够确定所有化合物的绝对构型及其构象分析。这是铼配合物的首次VCD研究，进一步证明了VCD光谱在确定无机配合物手性方面的适用性。
