排序方式: 共有57条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
The structural features of quinone ligands are diagnostic of charge. The o-benzoquinone, radical semiquinonate, and catecholate electronic forms have C-O bond lengths and a pattern of ring C-C bond lengths that point to a specific mode of coordination. This correlation between ligand charge and structure has been extended to iminoquinone and iminothioquinone ligands, giving a charge-localized view of electronic structure for complexes of redox-active metal ions. The radical semiquinonate form of these ligands has been found to be a surprisingly common mode of coordination; however, the paramagnetic character of the radical ligand is often obscured in complexes containing paramagnetic metal ions. In this report, diamagnetic iminosemiquinonate (isq) and iminothiosemiquinonate (itsq) complexes of ls-d(5) Ru(III) with related complexes of osmium are reported. With osmium, the Os(IV)-amidophenolate (ap) redox isomer is formed. Electrochemical and spectral properties are described for Ru(PPh(3))(2)(isq)Cl(2), Ru(PPh(3))(2)(itsq)Cl(2), Os(PPh(3))(2)(ap)Br(2), Os(PPh(3))(2)(atp)Br(2), and Os(PPh(3))(2)(ap)H(2). Crystallographic characterization of Ru(PPh(3))(2)(isq)Cl(2), Ru(PPh(3))(2)(itsq)Cl(2), and Os(PPh(3))(2)(ap)H(2) was used to assign charge distributions. 相似文献
9.
Cortlandt G. Pierpont 《Journal of Chemical Sciences》2002,114(4):247-254
The properties of transition metal complexes containing catecholate and radical semiquinonate ligands have often been found
to be unusual and unexpected. Crystals of Rh(CO)2(3,6-DBSQ), containing the 3,6-di-tert-butyl-1,2-semiquinonate ligand, form as long thin needles that are observed to bend
reversibly upon irradiation with NIR light. Crystallographic characterization reveals a stacked solid state lattice with planar
molecules aligned with metal atoms atop one another. Electronic spectra recorded in the solid state and in solution show an
intense band at 1600 nm that maps the energy dependence of crystal bend angle. The transition is a property of the stacked
assembly, rather than of an individual complex molecule, and appears associated with an MLCT process that transfers charge
from an antibonding band formed by interacting Rhd
z
2
orbitals to the vacant quinone π* orbital. Related observations have been made on the [Co(μ-pyz)(3,6-DBSQ)(3,6-DBCat)]npolymer. Photomechanical properties appear associated with electronic transitions that lead to a physical change in axial
length of a linear polymer, coupled with a soft solid state lattice that permits axial contraction/expansion without crystal
fracture. 相似文献
10.