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Crystal structure determination of bis‐dimethyl heptamethine cyanine chloride, C 11 N 2 H 19 Cl · 4 H 2 O
Author(s) -
Kulpe S.,
Kuban R.J.,
Schulz B.,
Dähne S.
Publication year - 1987
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170220315
Subject(s) - chemistry , monoclinic crystal system , crystal structure , cyanine , crystallography , molecule , bond length , hydrogen bond , valence (chemistry) , stacking , x ray crystallography , diffraction , physics , organic chemistry , quantum mechanics , fluorescence , optics
Mr = 286.59, monoclinic superposition structure C 121, Z = 4, a = 15.248(3), b = = 6.942 (3), c = 9.074(1) Å, β = 120.1(1)°, V = 827(1) Å 3 , D m = 1.13(1) Mg m −3 , D x = = 1.15 Mg m −3 , λ(MoK α ) = 0.71069 Å, μ = 0.243 mm −1 , F (000) = 312, T = 296 K, final R = 0.061 for 802 reflections. All hydrogen atoms were located. The structure consists of chloride anions, bis‐dimethyl heptamethine cyanine cations and water molecules. The structure of bis‐dimethyl heptamethine cyanine chloride is disordered, e.g. there exist partial coincidence operations, leading to more than one stacking mode of the bis‐dimethyl heptamethin cyanine chains. The crystal structure consists of rows of molecule along the a ‐axis. The CC bonds show the bond length compensation, typical of polymethines, towards a partial double bond (mean value 1.38 Å) between formally sp 2 ‐hybridized C atoms. The CN bond lengths to the methyl carbon atoms (mean value 1.49 Å) correspond to normal CN single bonds. The valence angles at the C atoms of the heptamethine chain clearly alternate and deviate systematically from 120°. This is also observed in other structures of a similar type. The structure determined by X‐ray analysis confirms the chemical results.