X-ray and spectroscopy studies of antisymbiotic effect O-coordination of the 4-methoxy benzoyl methylene triphenyl phosphorane ligand in palladium(II) complex
摘要:
Complex [Pd(C6H4CH2NH2-k(2)-C,N)(Py)(OC (MeO-4-C6H4)=CH-PPh3)]OTf (1) (OTf = CF3SO3) represents the example of an ylide O-bound to a Pd(II) center that is unusual for the classical soft metals. O-coordination of ylides and cisoid structure of complex was demonstrated by single-crystal X-ray analyses and spectroscopy. The IR and NMR data of the product (1), formed by the reaction of Pd( II) with the same ylide, are similar to those of O-bounded ylide. Analytical data indicate a 1:1 stoichiometry between the ylide and Pd (II) in the product (1). The molar conductivity of (1) Lambda = 175 Omega (1) mol (1) cm(2) is within the range for 1:1electrolytes. (C) 2008 Elsevier B.V. All rights reserved.
叔和伯苄胺[Pd(C6H4CHR%NR2)Cl(py)]的环钯配合物促进Nt-BOC-S-蛋氨酸对硝基苯酯(5)的水解动力学,其中R Me(1)和H(3),R%H(a),S-Me(b)和R-Me(b)已被研究。在缓冲溶液中,配合物1和3分别进行氯配体的水合反应,得到物种2和4,它们根据pH 8和25°C下的速率表达kobs ko kcat [Pd(II)] t进行水解。络合物2a-c,4a-c的kcat途径的速率常数分别等于2.5、2.1、2.2、32、220和260 M 1 s 1,表明苄胺(4a)和α-甲基苄胺(4b,c )配合物分别比N,N-二甲基苄胺配合物2a催化活性高大约十倍和一百倍。当活化的酯具有能够与Pd(II)结合的供体中心时,观察到这种剧烈的区分。与此相一致的是,所有研究的络合物在乙酸2,4-二硝基苯酯的水解中均显示出相似的活性(kcat:0.8 M 1 s 1)。推测在