Axial coordination and conformational heterogeneity of nickel(II) tetraphenylporphyrin complexes with nitrogenous bases

被引:64
作者
Jia, SL
Jentzen, W
Shang, M
Song, XZ
Ma, JG
Scheidt, WR
Shelnutt, JA
机构
[1] Sandia Natl Labs, Mat Theory & Computat Dept, Albuquerque, NM 87185 USA
[2] Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA
[3] Univ Essen Gesamthsch, Nukl Med Klin & Poliklin, D-45147 Essen, Germany
[4] Univ Notre Dame, Dept Chem & Biochem, Notre Dame, IN 46556 USA
关键词
D O I
10.1021/ic980289+
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Axial ligation of nickel(II) 5,10,15,20-tetraphenylporphyrin (NiTPP) with pyrrolidine or piperidine has been investigated using X-ray crystallography, UV-visible spectroscopy, resonance Raman spectroscopy, and molecular mechanics (MM) calculations. By varying the pyrrolidine concentration in dichloromethane, distinct nu(4) Raman lines are found for the four-, five-, and six-coordinate species of NiTPP. The equilibrium constants for addition of the first and second pyrrolidine axial ligands are 1.1 and 3.8 M-1, respectively. The axial ligands and their orientations influence the type and magnitude of the calculated nonplanar distortion. The differences in the calculated energies of the conformers having different ligand rotational angles are small so they may coexist in solution. Because of the similarity in macrocyclic structural parameters of these conformers and the free rotation of the axial ligands, narrow and symmetric nu(2) and nu(8) Raman lines are observed. Nonetheless, the normal-coordinate structural-decomposition analysis of the nonplanar distortions of the calculated structures and the crystal structure of the bis(piperidine) complex reveals a relationship between the orientations of axial ligand(s) and the macrocyclic distortions. For the five-coordinate complex with the plane of the axial ligand bisecting the Ni-N-pyrrole bonds, a primarily ruffled deformation results. With the ligand plane eclipsing the Ni-N-pyrrole bonds, a mainly saddled deformation occurs. With the addition of the second axial ligand, the small doming of the five-coordinate complexes disappears, and ruffling or saddling deformations change depending on the relative orientation of the two axial ligands. The crystal structure of the NiTPP bis(piperidine) complex shows a macrocycle distortion composed of wav(x) and wav(y) symmetric deformations, but no ruffling, saddling, or doming. The difference in the calculated and observed distortions results partly from the phenyl group orientation imposed by crystal packing forces. NIM calculations predict three stable conformers (ruf, sad, and planar) for four-coordinate NiTPP, and resonance Raman evidence for these conformers was given previously.
引用
收藏
页码:4402 / 4412
页数:11
相关论文
共 69 条
[1]  
ABRAHAM RJ, 1969, J CHEM SOC B, V8, P903
[2]   PORPHYRINS .20. THEORY FOR STATES OF NI(D8) COMPLEXES [J].
AKE, RL ;
GOUTERMA.M .
THEORETICA CHIMICA ACTA, 1970, 17 (05) :408-&
[3]   INFLUENCES OF PI-PI-COMPLEX FORMATION, DIMERIZATION, AND BINDING TO HEMOGLOBIN ON THE PLANARITY OF NICKEL(II) PORPHYRINS [J].
ALDEN, RG ;
ONDRIAS, MR ;
SHELNUTT, JA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1990, 112 (02) :691-697
[4]   RUFFLING OF NICKEL(II) OCTAETHYLPORPHYRIN IN SOLUTION [J].
ALDEN, RG ;
CRAWFORD, BA ;
DOOLEN, R ;
ONDRIAS, MR ;
SHELNUTT, JA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1989, 111 (06) :2070-2072
[5]   PLANAR NONPLANAR CONFORMATIONAL EQUILIBRIUM IN METAL DERIVATIVES OF OCTAETHYLPORPHYRIN AND MESO-NITROOCTAETHYLPORPHYRIN [J].
ANDERSON, KK ;
HOBBS, JD ;
LUO, LA ;
STANLEY, KD ;
QUIRKE, JME ;
SHELNUTT, JA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1993, 115 (26) :12346-12352
[6]   IDENTIFICATION OF ISOMERIC MESO-DIOXO DERIVATIVES OF OCTAETHYLPORPHYRIN AND SEPARATION AND STRUCTURAL CHARACTERIZATION OF THE NICKEL(II) COMPLEXES [J].
BALCH, AL ;
OLMSTEAD, MM ;
PHILLIPS, SL .
INORGANIC CHEMISTRY, 1993, 32 (18) :3931-3936
[7]   STRUCTURAL AND THEORETICAL-MODELS OF PHOTOSYNTHETIC CHROMOPHORES - IMPLICATIONS FOR REDOX, LIGHT-ABSORPTION PROPERTIES AND VECTORIAL ELECTRON FLOW [J].
BARKIGIA, KM ;
CHANTRANUPONG, L ;
SMITH, KM ;
FAJER, J .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1988, 110 (22) :7566-7567
[8]  
DUVAL H, 1997, ACTA CRYSTALLOGR C, V53, P10270
[9]   UNUSUAL PICOSECOND (1)(PI,PI-ASTERISK) DEACTIVATION OF RUFFLED NONPLANAR PORPHYRINS [J].
GENTEMANN, S ;
MEDFORTH, CJ ;
EMA, T ;
NELSON, NY ;
SMITH, KM ;
FAJER, J ;
HOLTEN, D .
CHEMICAL PHYSICS LETTERS, 1995, 245 (4-5) :441-447
[10]   REFINED STRUCTURE OF CYTOCHROME-C3 AT 1.8 A RESOLUTION [J].
HIGUCHI, Y ;
KUSUNOKI, M ;
MATSUURA, Y ;
YASUOKA, N ;
KAKUDO, M .
JOURNAL OF MOLECULAR BIOLOGY, 1984, 172 (01) :109-139