Crystal structure of tricarbonyl-chlorido-(2E)-2-(6-(E-(2-hydroxyphenylimino) methyl)pyridine-2-yl)methyleneaminophenol-rhenium(I), C22H15ClN3O5Re

Abstract

Source of material (2E)-2-(6-(E-(2-hydroxyphenylimino)methyl)pyridine-2-yl)-methyleneaminophenol was reacted with Re(CO) 5 Cl in amixture of toluene anddichloromethane.Crystals suitablefor the diffraction study were obtainedupon evaporation of the reaction mixtureatambientconditions. Experimental detailsCarbon-boundHatoms were placed in calculated positions(C-H 0.95 Å) andwereincludedinthe refinement in the riding model approximation, with U iso (H) setto1.2U eq (C). The Hatoms of the hydroxylgroups were allowed to rotate with afixed angle around the C-O bonds to best fit the experimental electron density (HFIX 147 in the SHELX program suite [14]), with U iso (H) sett o 1.5U eq (O). DiscussionNext to cardiovascular diseases, cancer has become one of the main fatal diseases in industrialized countries. Apart fromclassical surgery,chemo-and radiotherapeutic treatments have entered the arsenal of possible cures for certain types of cancer. All methods, however, suffer from theirown setofproblematic side-effects and, as ac onsequence, the development of radiopharmaceuticals -combining the advantages of chemotherapy as well as radiation methods while at the sametimeavoiding their unique respectiveundesiredside-effects -has been atopic of research [1,2].T ailoring andf ine-tuning of thee nvisionedr adiopharmaceuticals' properties such as lipophilicityand,inparticular, inertness is of paramountimportancewithrespect to possible future in vivo applications in contemporary medicine and requires sound knowledge about structural parameters of the ligands applied if a more heuristic approach in the synthesis is to triumph over pure trial-and-error as it is encountered in this specific field of coordination chemistry up to the present day. In continuation of our interest in rhenium-based coordination compounds that might serve as radiopharmaceuticals,t he titlec ompoundw as synthesized. The molecular and crystal structure of four other rhenium coordination compounds featuring as ymmetric double-Schiff base ligand have been reported earlier [3][4][5][6] as has one rhenium(I) coordination compound that features half the title compound's Schiff base ligand in its coordination sphere [7]. The title compound is ah exacoordinate rhenium(I) coordination compound. The octahedral coordination sphere is constructed by three carbonyl ligands in fac-configuration, as well as ac hlorido ligand and asymmetric two-fold Schiff-base, the latter coordinating via the pyridyl-type nitrogen atom as well as one of the imine-group nitrogen atoms. Apuckering analysis of the five-membered chelate ring according to Cremer &P ople [8]

The crystal structure of N-(4-(cyclohexylimino)pent-2-en-2-yl)cyclohexanamine, C17H30N2

“…Imines are easily obtained upon condensation reaction of primary amines with carbonyles (aldehydes and ketones alike). They have found application as ligands in transition metal chemistry, and their role as potential chelating agents has been confirmed on grounds of diffraction studies based on single crystals [7][8][9][10][11]. In continuation of our interest in the structural aspects of diverse imine compounds [12][13][14][15][16][17][18] the title compound was synthesized and investigated by means of a diffraction study based on single crystals.…”