Phosphine oxide functionalised with two bipyridine subunits: a novel ligand for the engineering of sterically hindered complexes
作者:Laurent Douce、Loïc Charbonnière、Michèle Cesario、Raymond Ziessel
DOI:10.1039/b102520c
日期:——
Ligand L, containing two 6-methyl-6′-methyl-yl-2,2′-bipyridine moieties linked by a “PhPO” spacer, has been prepared. Subsequent complexation with [Cu(CH3CN)4](BF4) led to a unique complex of formula [CuL](BF4). The molecular structure has been determined by X-ray crystallography in the solid state and NMR studies in solution. The complex displays an intense absorption band in the visible wavelength range with maxima at 418 and 509 nm, and
is oxidised reversibly at +0.66 V (ΔEp
= 80 mV) to the corresponding Cu(II) species, while two successive reductions of the coordinated bipyridine fragments occur at −1.60 (ΔEp
= 66) and −1.84 V (ΔEp
= 70 mV) s. SCE. Direct spectrophotometric titrations with global analysis allowed us to elicit stability constants for the emergent complex and to highlight the formation of a dinuclear complex in the presence of excess copper.
已制备出配体L,其中包含两个由“PhPO”间隔物连接的6-甲基-6′-甲基-2,2′-联吡啶基团。随后与[Cu(CH3CN)4](BF4)络合,形成独特的[CuL](BF4)络合物。通过固态X射线晶体学和溶液核磁共振研究确定了分子结构。该络合物在可见光波长范围内显示出强烈的吸收带,最大吸收波长为418和509 nm,在+0.66 V(ΔEp=80 mV)下可逆氧化为相应的Cu(II)物种,而配位联吡啶片段在-1.60(ΔEp=66)和-1.84 V(ΔEp=70 mV)s. SCE下发生两次连续还原。通过直接分光光度滴定法进行全局分析,我们获得了新络合物的稳定性常数,并发现了在过量铜存在下形成二核络合物的情况。