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Synthesis, structural characterization, EPR spectroscopy and Hirshfeld surface analysis of a novel Cu 2+ ‐doped 3,14‐diethyl‐2,13‐diaza‐6,17‐diazoniatricyclo[16.4.0.0 7,12 ]docosane bis(perchlorate)
Author(s) -
Moncol Jan,
Mazúr Milan,
Valko Marian,
Choi Jong-Ha
Publication year - 2019
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229619005588
Subject(s) - crystallography , cyclam , macrocyclic ligand , crystal structure , chemistry , perchlorate , hydrogen bond , ligand (biochemistry) , molecule , electron paramagnetic resonance , stereochemistry , metal , ion , receptor , organic chemistry , nuclear magnetic resonance , biochemistry , physics
Cyclam derivatives and their metal complexes have been found to exhibit an anti‐HIV effect and stimulate the activity of stem cells from bone marrow. The strength of their binding to the CXCR4 receptor correlates with anti‐HIV and stem‐cell activities. Knowledge of the conformation and crystal packing of various macrocyclic metal complexes has become important in developing new effective anti‐HIV drugs. The synthesis and preparation of single crystals of a new Cu 2+ ‐doped macrocyclic compound, (3,14‐diethyl‐2,6,13,17‐tetraazatricyclo[16.4.0.0 7,12 ]docosane)copper(II) bis(perchlorate)–3,14‐diethyl‐2,13‐diaza‐6,17‐diazoniatricyclo[16.4.0.0 7,12 ]docosane bis(perchlorate) (0.69/0.31), {[Cu(C 22 H 44 N 4 )](ClO 4 ) 2 } 0.69 ·(C 22 H 46 N 4 2+ ·2ClO 4 − ) 0.31 , is reported. Characterization by X‐ray diffraction analysis shows that the asymmetric unit contains half of a centrosymmetric molecule. The macrocyclic ligand in the compound adopts the most stable trans ‐III conformation. The Cu—N distances of 2.015 (3) and 2.047 (3) Å are normal, but the long axial Cu—O bond of 2.795 (3) Å may be due to a combination of the Jahn–Teller effect and the strong in‐plane ligand field. The crystal structure is stabilized by hydrogen bonding between secondary N—H groups, the N atoms of the macrocycle and the O atoms of the perchlorate anions. Hirshfeld surface analysis with 2D (two‐dimensional) fingerprint plots indicates that the main contributions to the crystal packing are from H…H (58.0%) and H…O/O…H (41.9%) interactions. Electron paramagnetic resonance (EPR) properties are also described.