Abstract
The reactions of 2,3-bis(2-pyridyl)quinoxaline (bpq) with CoCl2·6H2O, Ag(CH3CN)4)BF4, and PdCl2(C6H5CN)2 produce [CoCl2(bpq)]2·2CHCl3, [Ag(bpq)CH3CN]2(BF4)2· 2CH3CN, and [PdCl2(bpq)], respectively. All the products are discrete 1:1 (metal:bpq) adducts, where the chelation mode of the bpq is dependent upon the metal atoms. The structure of [CoCl2(bpq)]2·2CHCl3 is a centrosymmetric Cl-bridged four-membered dimer, [Co2Cl2], in which the bpq is bonded to the cobalt(II) atom in an anisobidentate mode with the nitrogen donors of pyridine and pyrazine rings. For [Ag(bpq)CH3CN]2(BF4)2· 2CH3CN, each bpq ligand connects two tetrahedral silver(I) ions in a tridentate mode, resulting in a cationic cyclic dimer. The structure of [PdCl2(bpq)] approximates to a molecular rocking chair with an isobidentate bpq through the nitrogen donors of 2-pyridyl rings. The compounds exhibit significant and characteristic relationships between the structures and their thermal properties. For [CoCl2(bpq)]2·2CHCl3, the solvate chloroform molecules are safely contained up to 144°C, but drastically evaporate above this temperature. The striking feature of [Ag(bpq)CH3CN]2(BF4)2· 2CH3CN is that the skeletal cyclic dimer is basically retained after dissociation of the coordinated acetonitriles in the solid state.
Original language | English |
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Pages (from-to) | 93-99 |
Number of pages | 7 |
Journal | Inorganica Chimica Acta |
Volume | 312 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2001 Jan 29 |
Bibliographical note
Funding Information:This research was supported financially by the Ministry of Science and Technology in Korea. We would like to thank Dr Sang-gi Lee for helpful discussion.
Keywords
- 2,3-Bis(2-pyridyl)quinoxaline complexes
- Crystal structures
- Thermal properties
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry