Structures and redox properties of metal complexes of the electron-deficient diphosphine chelate ligand R,R-quinoxP. Organometallics, (27)2:218--223, 2008. [PUMA: crystal complex carbonyl structure complex;electroredn structure;platinum platinum complex;palladium diphosphinoquinoxaline structure;rhenium group complex;electrooxidn prepn]