Synthesis of zinc, copper, nickel, cobalt, and iron complexes using tris(pyrazolyl)methane sulfonate ligands: a structural model for N,N,O binding in metalloenzymes.
Ligands of intermediate steric bulk were designed to mimic metalloenzymes with histidine and carboxlyate binding sites. The reaction between tris(3-isopropylpyrazolyl)methane and butyllithium followed by SO3NMe3 in THF yielded the new ligand lithium tris(3-isopropylpyrazolyl)methane sulfonate (LiTpmsiPr). Various metal salts reacted with LiTpmsiPr to give the octahedral complexes M(TpmsiPr)2 (M = Zn, Cu, Ni, Co, Fe) in which each ligand has N,N,O binding to the metal. In the reaction between LiTpmsiPr and ZnCl2, in addition to the major product Zn(TpmsiPr)2, [LiTpmsiPrZnCl2].2THF was also formed as a minor product with a tetrahedral zinc atom coordinated to either N,N,Cl,Cl in the solid phase or N,N,N,Cl in acetonitrile solution. Although TpmsiPr is coordinatively flexible and can act as a bipodal or tripodal ligand, it appears to favor the formation of octahedral L2M complexes.
Papish
Elizabeth T
ET
Department of Chemistry, Salisbury University, 1101 Camden Avenue, Salisbury, Maryland 21801, USA. etpapish@salisbury.edu
Taylor
Michael T
MT
Jernigan
Finith E
FE
Rodig
Michael J
MJ
Shawhan
Robert R
RR
Yap
Glenn P A
GP
Jové
Fernando A
FA
D001665:Binding Sites; D015392:Chemistry, Inorganic / Q000379:methods*; D003035:Cobalt; D003300:Copper; D004798:Enzymes / Q000737:chemistry* / Q000378:metabolism*; D007501:Iron; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000737:chemistry / Q000378:metabolism*; D008956:Models, Chemical; D015394:Molecular Structure; D009532:Nickel; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D011720:Pyrazoles / Q000737:chemistry; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D013451:Sulfonic Acids / Q000737:chemistry; D015032:Zinc
D004798:Enzymes; D008024:Ligands; D008670:Metals; D011720:Pyrazoles; D013451:Sulfonic Acids; C515920:tris(pyrazolyl)methane; D003035:Cobalt; D003300:Copper; D009532:Nickel; D007501:Iron; D015032:Zinc; D009584:Nitrogen; D010100:Oxygen