Crystal Structure of Porphine

The crystal structure of porphine, the parent compound in the porphyrin series, was determined by x‐ray diffraction analysis. The phases of the normalized structure factors were obtained by the probability methods of Hauptman and Karle. The crystals are monoclinic with four molecules per unit cell, and the C2h5—P21/a space group requires no molecular symmetry. Observed small deviations from planarity are not large enough to be significant. Comparison of the crystal structures of several porphyrins indicates that the porphine skeleton is probably planar or nearly planar in the vapor phase, although marked ruffling occurs in some crystals because of crystal‐packing forces. The wide variation in molecular configuration found in different crystals emphasizes the easy deformability of the molecule; this property may be important in biological systems.

[1]  R. E. Marsh,et al.  To fit a plane or a line to a set of points by least squares , 1959 .

[2]  E. Fleischer,et al.  The Structure of Porphine1 , 1965 .

[3]  I. Karle,et al.  An application of the symbolic addition method to the structure of l‐arginine dihydrate , 1964 .

[4]  I. Karle,et al.  The structure of C8F12, a saturated dimer of hexafluorobutadiene , 1965 .

[5]  I. Karle,et al.  The crystal structures of deoxyanisoin and p,p'‐dimethoxybenzophenone , 1962 .

[6]  W. C. Hamilton.  On the isotropic temperature factor equivalent to a given anisotropic temperature factor , 1959 .

[7]  S. Krol.  Notes- A New Synthesis of Porphin , 1959 .

[8]  H. Norment.  The crystal and molecular structures of trans-(1,4),(5,8)-dimethylene-cis,anti,cis-perhydroanthraquinone , 1965 .

[9]  T. Hamor,et al.  The Structure of Crystalline Tetraphenylporphine. The Stereochemical Nature of the Porphine Skeleton , 1964 .

[10]  A. Tulinsky,et al.  The Triclinic Crystal Form of α,β,γ,δ-Tetraphenylporphine , 1964 .

[11]  M. B. Crute.  The crystal structure of nickel etioporphyrin II , 1959 .

[12]  E. W. Hughes,et al.  The Crystal Structure of Melamine , 1941 .

[13]  I. Karle,et al.  An application of a new phase determination procedure to the structure of cyclo(hexaglycyl)demihydrate , 1963 .

[14]  L. Pauling.  The Nature Of The Chemical Bond , 1939 .

[15]  C. K. Miller,et al.  Crystal and Molecular Structures of Some Metal Tetraphenylporphines , 1964 .

[16]  James A. Ibers,et al.  International tables for X-ray crystallography , 1962 .

[17]  T. Hámor,et al.  Configuration of the Porphine Skeleton in Unconstrained Porphyrin Molecules , 1963 .

[18]  E. Fleischer.  The Structure of Nickel Etioporphyrin-I , 1963 .

[19]  G. Badger,et al.  Porphyrins. VII. The synthesis of porphyrins by the Rothemund reaction , 1964 .

[20]  D. F. Koenig.  The structure of a-chlorohemin , 1965 .

[21]  D. Cruickshank,et al.  The crystal structure of benzene at — 3°C , 1958, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[22]  I. Karle.  The crystal structure of N‐benzyl‐l,4‐dihydronicotinamide , 1961 .

[23]  E. Becker,et al.  Proton Magnetic Resonance Studies of Porphyrins , 1961 .

[24]  E. Fleischer.  The Structure of Copper Tetraphenylporphine , 1963 .

[25]  G. S. Smith,et al.  Single‐crystal intensity measurements with the three‐circle counter diffractometer , 1962 .

[26]  S. H. YÜ,et al.  Determination of Absolute from Relative X-Ray Intensity Data , 1942, Nature.

[27]  A I Kitaigorodskii,et al.  Organic chemical crystallography , 1961 .

[28]  H. Hauptman,et al.  Crystal and molecular structure of p,p'‐dimethoxybenzophenone by the direct probability method , 1957 .

[29]  W. Caughey,et al.  The Crystal Structure and Molecular Stereochemistry of Methoxyiron (III) Mesoporphyrin-IX Dimethyl Ester1 , 1965 .

[30]  A. Camerman,et al.  The crystal and molecular structure of pyrene , 1965 .