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Cobalt(II) chloride complexes with 1,1′‐dimethyl‐4,4′‐bipyrazole featuring first‐ and second‐sphere coordination of the ligand
Author(s) -
Domasevitch Konstantin V.
Publication year - 2014
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229614002046
Subject(s) - cobalt , ligand (biochemistry) , chloride , chemistry , coordination sphere , coordination complex , medicinal chemistry , stereochemistry , crystallography , inorganic chemistry , organic chemistry , crystal structure , receptor , biochemistry , metal
In catena ‐poly[[dichloridocobalt(II)]‐μ‐(1,1′‐dimethyl‐4,4′‐bipyrazole‐κ 2 N 2 : N 2′ )], [CoCl 2 (C 8 H 10 N 4 )] n , (1), two independent bipyrazole ligands (Me 2 bpz) are situated across centres of inversion and in tetraaquabis(1,1′‐dimethyl‐4,4′‐bipyrazole‐κ N 2 )cobalt(II) dichloride–1,1′‐dimethyl‐4,4′‐bipyrazole–water (1/2/2), [Co(C 8 H 10 N 4 ) 2 (H 2 O) 4 ]Cl 2 ·2C 8 H 10 N 4 ·2H 2 O, (2), the Co 2+ cation lies on an inversion centre and two noncoordinated Me 2 bpz molecules are also situated across centres of inversion. The compounds are the first complexes involving N , N ′‐disubstituted 4,4′‐bipyrazole tectons. They reveal a relatively poor coordination ability of the ligand, resulting in a Co–pyrazole coordination ratio of only 1:2. Compound (1) adopts a zigzag chain structure with bitopic Me 2 bpz links between tetrahedral Co II ions. Interchain interactions occur by means of very weak C—H...Cl hydrogen bonding. Complex (2) comprises discrete octahedral trans ‐[Co(Me 2 bpz) 2 (H 2 O) 4 ] 2+ cations formed by monodentate Me 2 bpz ligands. Two equivalents of additional noncoordinated Me 2 bpz tectons are important as `second‐sphere ligands' connecting the cations by means of relatively strong O—H...N hydrogen bonding with generation of doubly interpenetrated pcu (α‐Po) frameworks. Noncoordinated chloride anions and solvent water molecules afford hydrogen‐bonded [(Cl − ) 2 (H 2 O) 2 ] rhombs, which establish topological links between the above frameworks, producing a rare eight‐coordinated uninodal net of {4 24 .5.6 3 } ( ilc ) topology.