Fujisawa Kiyoshi, Ono Tetsuya, Ishikawa Yoko, Amir Nagina, Miyashita Yoshitaro, Okamoto Ken-ichi, Lehnert Nicolai
Graduate School of Pure and Applied Sciences, University of Tsukuba, Japan.
Inorg Chem. 2006 Feb 20;45(4):1698-713. doi: 10.1021/ic051290t.
Copper(I) complexes with tripodal nitrogen-containing neutral ligands such as tris(3,5-diisopropyl-1-pyrazolyl)methane (L1') and tris(3-tertiary-butyl-5-isopropyl-1-pyrazolyl)methane (L3'), and with corresponding anionic ligands such as hydrotris(3,5-diisopropyl-1-pyrazolyl)borate (L1-) and hydrotris(3-tertiary-butyl-5-isopropyl-1-pyrazolyl)borate (L3-) were synthesized and structurally characterized. Copper(I) complexes [Cu(L1')Cl] (1), [Cu(L1')(OClO3)] (2), Cu(L1')(NCMe) (3a), Cu(L1')(NCMe) (3b), Cu(L1')(CO) (4a), and Cu(L1')(CO) (4b) were prepared using the ligand L1'. Copper(I) complexes [Cu(L3')Cl] (5) and Cu(L3')(NCMe) (6) with the ligand L3' were also synthesized. Copper(I) complexes [Cu(L1)(NCMe)] (7) and [Cu(L1)(CO)] (8) were prepared using the anionic ligand L1-. Finally, copper(I) complexes with anionic ligand L3- and acetonitrile (9) and carbon monoxide (10) were synthesized. The complexes obtained were fully characterized by IR, far-IR, 1H NMR, and 13C NMR spectroscopy. The structures of both ligands, L1' and L3', and of complexes 1, 2, 3a, 3b, 4a, 4b, 5, 6, 7, and 10 were determined by X-ray crystallography. The effects of the differences in (a) the fourth ligand and the counteranion, (b) the steric hindrance at the third position of the pyrazolyl rings, and most importantly, (c) the charge of the N3 type ligands, on the structures, spectroscopic properties, and reactivities of the copper(I) complexes are discussed. The observed differences in the reactivities toward O2 of the copper(I) acetonitrile complexes are traced back to differences in the oxidation potentials determined by cyclic voltammetry. A special focus is set on the carbonyl complexes, where the 13C NMR and vibrational data are presented. Density functional theory (DFT) calculations are used to shed light on the differences in CO bonding in the compounds with neutral and anionic N3 ligands. In correlation with the vibrational and electrochemical data of these complexes, it is demonstrated that the C-O stretching vibration is a sensitive probe for the "electron richness" of copper(I) in these compounds.
合成并通过结构表征了铜（I）与三脚架型含氮中性配体（如三（3,5-二异丙基-1-吡唑基）甲烷（L1'）和三（3-叔丁基-5-异丙基-1-吡唑基）甲烷（L3'））以及相应的阴离子配阴离子配体（如氢三（3,5-二异丙基-1-吡唑基）硼酸酯（L1-）和氢三（3-叔丁基-5-异丙基-1-吡唑基）硼酸酯（L3-））形成的配合物。使用配体L1'制备了铜（I）配合物[Cu（L1'）Cl]（1）、[Cu（L1'）（OClO3）]（2）、[Cu（L1'）（NCMe）]（PF6）（3a）、[Cu（L1'）（NCMe）]（ClO4）（3b）、[Cu（L1'）（CO）]（PF6）（4a）和[Cu（L1'）（CO）]（ClO4）（4b）。还合成了含配体L3'的铜（I）配合物[Cu（L3'）Cl]（5）和[Cu（L3'）（NCMe）]（PF6）（6）。使用阴离子配体L1-制备了铜（I）配合物[Cu（L1）（NCMe）]（7）和[Cu（L1）（CO）]（8）。最后，合成了含阴离子配体L3-与乙腈（9）和一氧化碳（10）的铜（I）配合物。通过红外光谱、远红外光谱、1H核磁共振光谱和13C核磁共振光谱对所得配合物进行了全面表征。通过X射线晶体学确定了配体L1'和L3'以及配合物1、2、3a、3b、4a、4b、5、6、7和10的结构。讨论了（a）第四配体和抗衡阴离子的差异、（b）吡唑环第三位的空间位阻，以及最重要的（c）N3型配体的电荷对铜（I）配合物的结构、光谱性质和反应活性的影响。观察到的铜（I）乙腈配合物对O2反应活性的差异可追溯到循环伏安法测定的氧化电位的差异。特别关注了羰基配合物，给出了其13C核磁共振和振动数据。使用密度泛函理论（DFT）计算来阐明含中性和阴离子N3配体的化合物中CO键合的差异。与这些配合物的振动和电化学数据相关联，证明C-O伸缩振动是这些化合物中铜（I）“电子丰富度”的灵敏探针。
