TY - JOUR
T1 - Synthesis, structure, and thermal behavior of discrete Co(II), Ag(I), and Pd(II) complexes with 2,3-bis(2-pyridyl)quinoxaline. Insight into coordination modes
AU - Jung, Ok Sang
AU - Park, Sung Ho
AU - Kim, Yun Ju
AU - Lee, Young A.
AU - Jang, Ho G.
AU - Lee, Uk
N1 - 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.
PY - 2001/1/29
Y1 - 2001/1/29
N2 - 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.
AB - 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.
KW - 2,3-Bis(2-pyridyl)quinoxaline complexes
KW - Crystal structures
KW - Thermal properties
UR - http://www.scopus.com/inward/record.url?scp=0035966475&partnerID=8YFLogxK
U2 - 10.1016/S0020-1693(00)00346-7
DO - 10.1016/S0020-1693(00)00346-7
M3 - Article
AN - SCOPUS:0035966475
VL - 312
SP - 93
EP - 99
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
SN - 0020-1693
IS - 1-2
ER -