Hydrogen bonded anion ribbons, networks and clusters and sulfur-anion interactions in novel radical cation salts of BEDT-TTF with sulfamate, pentaborate and bromide

Abstract

The novel radical cation salt (BEDT-TTF)3(sulfamate) 2·2H2O (BEDT-TTF = bis(ethylenedithio) tetrathiafulvalene) is semiconducting with donor stacks comprised of pairs of partially oxidized molecules and a single more highly oxidized molecule which is twisted out of the stack by ca. 30°. Hydrogen bonded pairs of sulfamate ions are linked into parallel ribbons by further hydrogen bonding between sulfamates and bridging water molecules. In contrast, the BEDT-TTF salt with pentaborate contains infinite layers formed of a network of hydrogen bonded pentaborate anions. Two new bromide salts of BEDT-TTF are reported, one is a semiconducting 1:1 salt in which the bromide is integrated among the BEDT-TTF donors, while the other contain a square of four bromide ions linked together by hydrogen bonding to a centrally located H5O2+ cation for every five BEDT-TTF molecules. © 2013 The Royal Society of Chemistry.