Zinc complexes of the biomimetic N,N,O ligand family of substituted 3,3-bis(1-alkylimidazol-2-yl)propionates: the formation of oxalate from pyruvate.
The coordination chemistry of the 2-His-1-carboxylate facial triad mimics 3,3-bis(1-methylimidazol-2-yl)propionate (MIm(2)Pr) and 3,3-bis(1-ethyl-4-isopropylimidazol-2-yl) propionate (iPrEtIm(2)Pr) towards ZnCl(2) was studied both in solution and in the solid state. Different coordination modes were found depending both on the stoichiometry and on the ligand that was employed. In the 2:1 ligand-to-metal complex [Zn(MIm(2)Pr)(2)], the ligand coordinates in a tridentate, tripodal N,N,O fashion similar to the 2-His-1-carboxylate facial triad. However, the 1:1 ligand-to-metal complexes [Zn(MIm(2)Pr)Cl(H(2)O)] and [Zn(iPrEtIm(2)Pr)Cl] were crystallographically characterized and found to be polymeric in nature. A new, bridging coordination mode of the ligands was observed in both structures comprising N,N-bidentate coordination of the ligand to one zinc atom and O-monodentate coordination to a zinc second atom. A rather unique transformation of pyruvate into oxalate was found with [Zn(MIm(2)Pr)Cl], which resulted in the isolation of the new, oxalato bridged zinc coordination polymer [Zn(2)(MIm(2)Pr)(2)(ox)].6H(2)O, the structure of which was established by X-ray crystal structure determination.
Bruijnincx
Pieter C A
PC
Chemical Biology and Organic Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Lutz
Martin
M
den Breejen
Johan P
JP
Spek
Anthony L
AL
van Koten
Gerard
G
Klein Gebbink
Robertus J M
RJ
D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008024:Ligands; D009942:Organometallic Compounds / Q000737:chemistry*; D010070:Oxalates / Q000138:chemical synthesis* / Q000737:chemistry; D011422:Propionates / Q000737:chemistry; D019289:Pyruvic Acid / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*