Document Type

Journal Article

Department/Unit

Department of Chemistry

Title

Dual coordination modes of ethylene-Linked NP2 ligands in cobalt(II) and nickel(II) Iodides

Language

English

Abstract

Here we report the syntheses and crystal structures of a series of cobalt(II) and nickel(II) complexes derived from RNP2 ligands (where R = OMeBz, HBz, BrBz, Ph) bearing ethylene linkers between a single N and two P donors. The CoII complexes generally adopt a tetrahedral configuration of general formula [(NP2)Co(I) 2], wherein the two phosphorus donors are bound to the metal center but the central N-donor remains unbound. We have found one case of structural isomerism within a single crystal structure. The CoII complex derived from BzNP2 displays dual coordination modes: one in the tetrahedral complex [(BzNP2)Co(I)2]; and the other in a square pyramidal variant, [(BzNP2)Co(I)2]. In contrast, the NiII complexes adopt a square planar geometry in which the P(Et)N(Et)P donors in the ligand backbone are coordinated to the metal center, resulting in cationic species of formula [(RNP2)Ni(I)]+ with iodide as counterion. All NiII complexes exhibit sharp 1H and 31P spectra in the diamagnetic region. The Co II complexes are high-spin (S = 3/2) in the solid state as determined by SQUID measurements from 4 to 300 K. Solution electron paramagnetic resonance (EPR) experiments reveal a high-spin/low-spin CoII equilibrium that is dependent on solvent and ligand substituent. © 2011 American Chemical Society.

Publication Date

2011

Source Publication Title

Inorganic Chemistry

Volume

50

Issue

20

Start Page

10213

End Page

10224

Publisher

American Chemical Society

DOI

10.1021/ic201213c

Link to Publisher's Edition

http://dx.doi.org/10.1021/ic201213c

ISSN (print)

00201669

ISSN (electronic)

1520510X

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