title: New structural forms in molecular metal phosphonates: novel tri- and hexanuclear zinc(II) cages containing phosphonate and pyrazole ligands.
abstract: The reaction of ZnCl(2) with tert-butylphosphonic acid and 3,5-dimethylpyrazole in the presence of triethylamine as a hydrogen chloride scavenger affords a trinuclear molecular zinc phosphonate [Zn(3)Cl(2)(3,5-Me(2)Pz)(4)(t-BuPO(3))(2)]. The structure of this compound contains a planar trizinc assembly containing two bicapping mu(3) [t-BuPO(3)](2-) ligands and terminal pyrazole and chloride ligands. In contrast an analogous reaction of ZnCl(2) with phenylphosphonic acid and 3,5-dimethylpyrazole affords a hexanuclear zinc phosphonate [Zn(6)Cl(4)(3,5-Me(2)PzH)(8)(PhPO(3))(4)]. The six zinc centers are arranged in a chairlike conformation. The four phosphonates in this complex also act as bridging tripodal mu(3) [RPO(3)](2-) ligands.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kanpur, India 208016. vc@iitk.ac.in
authors.forename: Vadapalli
authors.initials: V
authors.lastname: Chandrasekhar
authors.forename: Savariraj
authors.initials: S
authors.lastname: Kingsley
authors.forename: Brian
authors.initials: B
authors.lastname: Rhatigan
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Lam
authors.forename: Arnold L
authors.initials: AL
authors.lastname: Rheingold