Pecak Jan, Eder Wolfgang, Tomsu Gerald, Stöger Berthold, Pignitter Marc, Kirchner Karl
Institute of Applied Synthetic Chemistry Vienna University of Technology Getreidemarkt 9 A-1060 Wien Austria.
X-Ray Centre Vienna University of Technology Getreidemarkt 9 1060 Wien Austria.
Eur J Inorg Chem. 2021 Nov 8;2021(41):4280-4285. doi: 10.1002/ejic.202100643. Epub 2021 Oct 11.
A series of cobalt complexes, stabilized by a monoanionic tridentate NCN pincer ligand, was synthetized and characterized. Preparation of the paramagnetic 15 VE complex [Co(NCN-Et)Br] () was accomplished by transmetalation of Li[2,6-(EtNCH)CH] with CoBr in THF. Treatment of this air-sensitive compound with NO gas resulted in the formation of the diamagnetic Co(III) species [Co(NCN-Et)(NO)Br] () as confirmed by X-ray diffraction. This complex features a strongly bent NO ligand (Co-N-O∠135.0°). The ν is observed at 1609 cm which is typical for a bent metal-N-O arrangement. Coordinatively unsaturated could further be treated with pyridine, isocyanides, phosphines and CO to form five-coordinate 17 VE complexes. Oxidation of with CuBr led to the formation of the Co(III) complex [Co(NCN-Et)Br]. Treatment of [Co(NCN-Et)Br] with TlBF as halide scavenger in acetonitrile led to the formation of the cationic octahedral complex Co(NCN-Et)(MeCN). A combination of X-ray crystallography, IR-, NMR- and EPR-spectroscopy as well as DFT/CAS-SCF calculations were used to characterize all compounds.
合成并表征了一系列由单阴离子三齿NCN钳形配体稳定的钴配合物。通过在四氢呋喃中用CoBr对Li[2,6-(EtNCH)CH]进行金属转移反应，制备了顺磁性的15价电子配合物[Co(NCN-Et)Br]（）。用NO气体处理这种对空气敏感的化合物，得到了抗磁性的Co(III)物种[Co(NCN-Et)(NO)Br]（），X射线衍射证实了这一点。该配合物具有一个强烈弯曲的NO配体（Co-N-O∠135.0°）。在1609 cm处观察到ν，这对于弯曲的金属-N-O排列来说是典型的。配位不饱和的（）可以进一步用吡啶、异腈、膦和CO处理，形成五配位的17价电子配合物。用CuBr氧化（）导致形成Co(III)配合物[Co(NCN-Et)Br]。在乙腈中用TlBF作为卤化物清除剂处理[Co(NCN-Et)Br]，导致形成阳离子八面体配合物Co(NCN-Et)(MeCN)。结合X射线晶体学、红外光谱、核磁共振光谱和电子顺磁共振光谱以及密度泛函理论/完全活性空间自洽场计算对所有化合物进行了表征。
