Copper(I) nitro complex with an anionic [HB(3,5-Me2Pz)3]− ligand: a synthetic model for the copper nitrite reductase active site.
The new copper(I) nitro complex [(Ph(3)P)(2)N][Cu(HB(3,5-Me(2)Pz)(3))(NO(2))] (2), containing the anionic hydrotris(3,5-dimethylpyrazolyl)borate ligand, was synthesized, and its structural features were probed using X-ray crystallography. Complex 2 was found to cocrystallize with a water molecule, and X-ray crystallographic analysis showed that the resulting molecule had the structure [(Ph(3)P)(2)N][Cu(HB(3,5-Me(2)Pz)(3))(NO(2))]·H(2)O (3), containing a water hydrogen bonded to an oxygen of the nitrite moiety. This complex represents the first example in the solid state of an analogue of the nitrous acid intermediate (CuNO(2)H). A comparison of the nitrite reduction reactivity of the electron-rich ligand containing the CuNO(2) complex 2 with that of the known neutral ligand containing the CuNO(2) complex [Cu(HC(3,5-Me(2)Pz)(3))(NO(2))] (1) shows that reactivity is significantly influenced by the electron density around the copper and nitrite centers. The detailed mechanisms of nitrite reduction reactions of 1 and 2 with acetic acid were explored by using density functional theory calculations. Overall, the results of this effort show that synthetic models, based on neutral HC(3,5-Me(2)Pz)(3) and anionic [HB(3,5-Me(2)Pz)(3)](-) ligands, mimic the electronic influence of (His)(3) ligands in the environment of the type II copper center of copper nitrite reductases (Cu-NIRs).
Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan. sodiohsu@kmu.edu.tw
Sodio C N
SC
Hsu
Yu-Lun
YL
Chang
Wan-Jung
WJ
Chuang
Hsing-Yin
HY
Chen
I-Jung
IJ
Lin
Michael Y
MY
Chiang
Chai-Lin
CL
Kao
Hsuan-Ying
HY
Chen
D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry*; D020134:Catalytic Domain; D003300:Copper / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009572:Nitrite Reductases / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry; D009574:Nitro Compounds / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D011720:Pyrazoles / Q000737:chemistry*; D011789:Quantum Theory
D008024:Ligands; D009573:Nitrites; D009574:Nitro Compounds; D009942:Organometallic Compounds; D011720:Pyrazoles; D003300:Copper; D009572:Nitrite Reductases; C052695:nitrite reductase, copper-containing