The formation of stable, undistorted octahedral transition metal complexes which contain a trans-spanning bidentate ligand remains a synthetic challenge. The reported complexes are of the type trans-[Ru(Cl)(trpy)Ph2PC6H4CH2O(CO)Y(CO)OCH2C6H4PPh2}][PF6] [where trpy = 2,2â²â¶6â²,2â³-terpyridine and Y = (CH2)3 = C3SPAN, 6; (CH2)4 = C4SPAN, 7; or isophthalate = ISPAN, 8] and represent the first examples of trans-spanned transition metal complexes which display little bond angle distortion from octahedral geometry and also contain a bridging linkage which is stable towards oxidation, reduction and hydrolysis. These complexes were characterized by elemental analyses, cyclic voltammetry, conductivity and UV-VIS spectroscopy. COSY, HETCOR and variable temperature (1H and 13C) NMR spectra of the complexes are consistent with a flexible spanning linkage that does not demonstrate restricted rotation about either the PâCipso or the RuâP bonds while the X-ray crystal structure analysis of 7 showed that the spanning linkage is positioned to one side of the meridional chloride.
合成含有反式跨双齿
配体的稳定、无畸变的八面体过渡
金属复合物仍然是一项挑战。所报道的复合物属于反式[Ru(Cl)(trpy)Ph2PC6H4 O(CO)Y(CO)O C6H4PPh2}][PF6]类型(其中trpy=2,2â²â¶6â²,2â³-三联
吡啶,Y=(
CH2)3=
C3SPAN,6;( )4=
C4SPAN,7;或异苯二
甲酸=IS
PAN,8),是反式跨过渡
金属复合物的首批实例,它们与八面体几何结构相比几乎没有出现键角畸变,还包含一个桥联,该桥联在氧化、还原和
水解过程中稳定。通过元素分析、循环伏安法、电导率和紫外-可见光谱对这些复合物进行了表征。复合物的COSY、HETCOR和可变温度(1H和13C)核磁共振光谱与柔性跨联一致,该跨联不会限制围绕P-Cipso或Ru-P键的旋转,而7的X射线晶体结构分析表明,跨联位于子午线
氯的一侧。