摘要:

π antibonding interactions result from the overlap of a filled π symmetry ligand orbital with a filled metal d orbital. This antibonding plays an important role in the chemistry of π donor ligands such as oxo and alkoxide. It is in large part responsible for the lack of late transition metal complexes with terminal oxo ligands, and can explain some of the unusual chemistry of late metal alkoxide complexes.

ISSN:0260-3594    

DOI:10.1080/02603598808035790

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Because the substitution reactions of transition-metal complexes can be controlled precisely by the choice of the metal and the ligands, and because these complexes have various spectroscopic and electrochemical properties, they are well-suited for many applications in biochemical and biophysical laboratories. Complex [Pt(trpy)Cl)+reacts, under mild conditions and noninvasively, with the exposed side chains of His, Cys, and even Arg residues in proteins. The derivatives can be separated chromatographically. The Pt(trpy)2+tags are stable. They are easily detected and quantitated owing to the strong UV-vis bands, whose positions and relative intensities depend on the identity and the environment of the tagged residue. The selectivity of Pt(II) chloro complexes as labeling reagents can be controlled by purposeful changes of the other three ancillary ligands. Treatment of Cys residues with (η5-C5H5)Fe(η5-C5H4HgCl)results in attachment of the redox-active ferrocenyl tag to the protein. Proteins can be cross-linked covalently through Met residues with the monometallictrans-PtL2Cl2reagents, and through His residues with the bimetallic Rh2(RCOO)4reagents. Cross-linking with the trimetallic reagent [Ru3(μ3-O)(μ2-OAc)6(H2O)3] may yield covalent triprotein clusters. A PtCl3- group attached to the Cys side chain in glutathione promotes selective hydrolysis of the Cys–Gly peptide bond. These findings point the way for the study of protein topography, of enzyme mechanism, of electron-transfer reactions in modified metalloproteins, of metal binding to Arg residues, and of protein cleavage by inorganic reagents.

ISSN:0260-3594    

DOI:10.1080/02603598808035791

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The interest in dealing with the classical phenomenon of second-sphere coordination has developed again during the past few years. This is due to some unusual chemical and physical properties caused by outer-sphere effects. Ion pair associates consisting of ionic Werner-type complexes and appropriate counter-ions are diverse representatives of second-sphere coordination. Such ion-pair compounds are of particular interest which are distinguished by spectroscopic ion pair charge transfer (IPCT) transitions. The spectroscopic and photochemical behavior of IPCT compounds, as well as a novel increment system for the prediction of the energy of optical IPCT transitions, are discussed in this Comment.

ISSN:0260-3594    

DOI:10.1080/02603598808035792

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0260-3594    

DOI:10.1080/02603598808035789

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor