title: A coordination chemistry dichotomy for icosahedral carborane-based ligands.
abstract: Although the majority of ligands in modern chemistry take advantage of carbon-based substituent effects to tune the sterics and electronics of coordinating moieties, we describe here how icosahedral carboranes-boron-rich clusters-can influence metal-ligand interactions. Using a series of phosphine-thioether chelating ligands featuring meta- or ortho-carboranes grafted on the sulfur atom, we were able to tune the lability of the platinum-sulfur interaction of platinum(II)-thioether complexes. Experimental observations, supported by computational work, show that icosahedral carboranes can act either as strong electron-withdrawing ligands or electron-donating moieties (similar to aryl- or alkyl-based groups, respectively), depending on which atom of the carborane cage is attached to the thioether moiety. These and similar results with carborane-selenol derivatives suggest that, in contrast to carbon-based ligands, icosahedral carboranes exhibit a significant dichotomy in their coordination chemistry, and can be used as a versatile class of electronically tunable building blocks for various ligand platforms.
authors.affiliation: Department of Chemistry and the International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, lllinois 60208, USA.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Spokoyny
authors.forename: Charles W
authors.initials: CW
authors.lastname: Machan
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Clingerman
authors.forename: Mari S
authors.initials: MS
authors.lastname: Rosen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Wiester
authors.forename: Robert D
authors.initials: RD
authors.lastname: Kennedy
authors.forename: Charlotte L
authors.initials: CL
authors.lastname: Stern
authors.forename: Amy A
authors.initials: AA
authors.lastname: Sarjeant
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin
mesh_terms: D001880:Boranes / Q000737:chemistry*; D008024:Ligands
chemical_list: D001880:Boranes; D008024:Ligands