Department of Chemistry, Indian Institute of Technology Delhi, New Delhi, 110016, India.
Dalton Trans. 2012 Feb 21;41(7):1931-7. doi: 10.1039/c1dt11695a. Epub 2011 Nov 18.
The new selenated Schiff bases L1-L4 which differ in the chain lengths (longest in L4) of non-coordinating substituents and their square planar complexes [Pd(L-H)Cl] (1-4) [L = L1-L4, behaving as (Se, N, O(-)) ligand] have been synthesized and characterized by multinuclei NMR. The molecular structure of 1 has been elucidated by X-ray diffraction on its single crystal [Pd-Se = 2.3965(9) Å]. All the complexes 1-4 (0.5 mol%) have been found suitable to catalyze Suzuki-Miyaura coupling reactions under mild conditions. The activity of 4 which has ligand L4 has been found highest. The formation of palladium(0) nano-particles (NPs) stablilized by organoselenium species appears to be the catalytic pathway. The length of the pendent alkyl chain present in the complex molecule unprecedentedly controls the dispersion and composition of these particles and consequently the catalytic activity.
已合成并通过多核 NMR 对具有不同非配位取代基链长（L4 最长）的新型硒代希夫碱 L1-L4 及其四方平面配合物 [Pd(L-H)Cl]（1-4）[L = L1-L4，作为（Se、N、O(-)）配体]进行了表征。通过对其单晶的 X 射线衍射解析阐明了 1 的分子结构 [Pd-Se = 2.3965(9) Å]。发现所有配合物 1-4（0.5 mol%）都适合在温和条件下催化 Suzuki-Miyaura 偶联反应。具有配体 L4 的 4 的活性最高。由有机硒物种稳定的钯 (0) 纳米颗粒 (NPs) 的形成似乎是催化途径。在配合物分子中存在的悬垂烷基链的长度前所未有地控制了这些颗粒的分散和组成，从而控制了催化活性。
