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Alkali metal complexes of 6‐methyl‐2‐pyridone: simple formulae, but not so simple structures
Author(s) -
Clegg William,
Tooke Duncan M.
Publication year - 2013
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
eISSN - 2052-5206
pISSN - 2052-5192
DOI - 10.1107/s2052519213025980
Subject(s) - chemistry , molecule , alkali metal , solvent , crystallography , metal , coordination number , ion , hydrogen bond , metal ions in aqueous solution , coordination sphere , atom (system on chip) , transition metal , inorganic chemistry , crystal structure , organic chemistry , computer science , embedded system , catalysis
Reaction of 6‐methyl‐2‐pyridone (Hmhp) with Na or K metal, or with Rb or Cs 2‐ethylhexoxide, in an appropriate single or mixed solvent, yields a series of solvated polymeric complexes with the empirical formulae M (mhp)(H 2 O) 2 [(1), M = Na; (2), M = K], M (mhp)(H 2 O) [(3), M = Rb; (4), M = Cs] and Cs(mhp)( R OH) [(5), R = Me; (6), R = Et]. All of the products have been crystallographically characterized and show sheet polymeric structures, except for a double‐chain structure for (2). In all of the structures, mhp − and solvent molecules function as bridging ligands; two metal ions are bridged (μ 2 ) by each solvent molecule in (1), (5) and (6), while (2) contains both μ 2 and μ 3 triple bridges, and (3) and (4) display highly unusual μ 4 quadruple bridging of metal ions by water molecules. The pyridonate O atom bridges two or three metal ions in each case. Nitrogen is also involved in coordination to the heavier metals; it bonds to a single ion in (3) and (4), but has an almost unprecedented bridging role in (5) and (6). As a result of the extensive bridging by ligands, coordination numbers between 6 and 8 are achieved for the metal ions. In each structure, all solvent OH groups form hydrogen bonds to pyridonate O and, in some cases, N atoms. With one exception, these are the first reported pyridonate complexes of the alkali metals Na–Cs that do not also include transition metals.