Pyrazine as a building block for molecular architectures with PtII

Michael Willermann; Clodagh Mulcahy; Roland K O Sigel; Marta Morell Cerdà; Eva Freisinger; Pablo J Sanz Miguel; Michael Roitzsch; Bernhard Lippert

doi:10.1021/ic051966k

Pyrazine as a building block for molecular architectures with PtII

Inorg Chem. 2006 Mar 6;45(5):2093-9. doi: 10.1021/ic051966k.

Authors

Michael Willermann¹, Clodagh Mulcahy, Roland K O Sigel, Marta Morell Cerdà, Eva Freisinger, Pablo J Sanz Miguel, Michael Roitzsch, Bernhard Lippert

Affiliation

¹ Fachbereich Chemie, Universität Dortmund, 44221 Dortmund, Germany.

PMID: 16499371
DOI: 10.1021/ic051966k

Abstract

A series of pyrazine (pz) complexes containing cis-(NH(3))(2)Pt(II), (tmeda)Pt(II) (tmeda = N,N,N',N'-tetramethylethylenediamine), and trans-(NH(3))(2)Pt(II) entities have been prepared and characterized by X-ray crystallography and/or 1H NMR spectroscopy. In these compounds, the pz ligands act as monodentate (1-3) or bidentate bridging ligands (4-7). Three variants of the latter case are described: a dinuclear complex [Pt(II)]2 (4b), a cyclic tetranuclear [Pt(II)](4) complex (5), and a trinuclear mixed-metal complex [Pt2Ag] (7). Mono- and bidentate binding modes are readily differentiated by 1H NMR spectroscopy, and the assignment of pz protons in the case of monodentate coordination is aided by the observation of (195)Pt satellites. Formation of the open molecular box cis-[{(NH3)2Pt(pz)}4](NO3)8.3.67H2O (5) from cis-(NH3)2Pt(II) and pz follows expectations of the "molecular library approach" for the generation of a cyclic tetramer.