title: Geometry and Spin Change at the Heart of a Cobalt(II) Complex: A Special Case of Solvatomorphism.
abstract: Structural analysis and spectroscopic methods revealed a special case of solvatomorphism: hydrogen-bonding-induced geometry and spin change within a same N,O-(bis)chelate of cobalt(II). Solid-state structures are presented for both the tetrahedral and the solvated square-planar forms of the complex. Magnetic-moment measurements and ESR spectroscopy confirmed the high-spin state of the tetrahedral form (μeff =4.7 μB ) and the low-spin state of the square-planar solvatomorph. Specific hydrogen-bonding interactions between the solvent molecules and the complex chelate ring (O1⋅⋅⋅H-CHCl2 (d=2.26 Å, D=3.24 Å, θ=173°); O2⋅⋅⋅H-CHCl2 (d=2.22 Å, D=3.19 Å, θ=165°)) play a pivotal role in biasing the system toward the low-spin ground state.
authors.affiliation: Département de Chimie, Université de Montréal, 2900 Edouard-Montpetit, Montréal, Québec, H3T-1J4 (Canada), Fax: (+001) 5143437586.
authors.forename: Mihaela
authors.initials: M
authors.lastname: Cibian
authors.affiliation: Département de Chimie, Université de Montréal, 2900 Edouard-Montpetit, Montréal, Québec, H3T-1J4 (Canada), Fax: (+001) 5143437586. garry.hanan@umontreal.ca.
authors.forename: Garry S
authors.initials: GS
authors.lastname: Hanan
keywords: N ligands; cobalt; coordination chemistry; solvatomorphism; structure elucidation