El-Metwally Nour

Synthesis, spectroscopic and thermal investigations of solid charge-transfer complexes of 1,4,7-trimethyl-1,4,7-triazacyclononane and the acceptors iodine, TCNE, TCNQ and chloranil

The solid charge-transfer complexes formed in the reaction of the electron donor 1,4,7-trimethyl-1,4,7-triazacyclononane (TMTACN) with the acceptors iodine, tetracyanoethylene (TCNE) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) have been isolated. These were characterized through electronic and infrared spectra as well as thermal and elemental analysis. The results show that the formed solid CT-complexes have the formulas [(TMTACN)I]I3, [(TMTACN)(TCNE)5] and [(TMTACN)(TCNQ)3] in full agreement with the known reaction stoichiometries in solution. The chloranil CT-solid complex cannot be isolated in pure form.

Resonance Raman and far infrared spectroscopic studies of triiodide complexes formed in the reaction of iodine with some polycyclic amines

Abstract The solid charge transfer complexes formed in the reaction of iodine with the polycyclic amines 1,4,8,12-tetraazacyclopentadecane (TACPD) and meso -5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (HMTACTD) have been investigated by resonance Raman and far i.r. spectroscopy. The spectra can be explained entirely by the presence of the I − 3 ion in these complexes, whose composition agreed fairly well with the formulas (TACPD) I + ·I − 3 and (HMTACTD) I + ·I − 3 . The three vibrations of the I − 3 ion, ν s (I—I), ν as (I—I) and δ(I − 3 ), are assigned at 109, 130 and 60 cm −1 for (TACPD)I + ·I − 3 . and at 110, 145 and 61 cm −1 for (HMTACTD) I + ·I − 3 . The structure and geometry of the I − 3 ion is discussed in view of the Raman and i.r. band activities.

Synthesis and Spectroscopic Studies of the Charge‐Transfer Complexes of 2,3‐Diaminopyridine and π‐Electron Acceptors

Abstract The spectrophotometric properties of the charge transfer (CT)‐complexes formed between 2,3‐diaminopyridine (DAPY) and π‐acceptors tetrachloro‐p‐benzoquinone (chloranil) and tetracyanoethylene (TCNE) have been studied in chloroform. The stoichiometry of these CT‐complexes is shown to be 1:1, (DAPY:chloranil) and 1:3 (DAPY:TCNE) forming complexes with the general formula [(DAPY)(chloranil)] and [(DAPY)(TCNE)3]. The two complexes were isolated as solids and further characterized by elemental analysis and infrared measurements.

Preparation and infrared spectra of (Cu(O)(H2O)3) and (Cu2(O) (C1)2(H2O)2) complexes formed in the reactions of Cu(II) salts with urea

Abstract The preparation and characterization of the new solid complexes (Cu(O)(H 2 O) 3 ) and (Cu 2 (O)(Cl) 2 (H 2 O) 2 ) formed in the reaction of urea with CuSO 4 · 5H 2 O and CuCl 2 · 2H 2 O, respectively, in aqueous media at ~75°C are reported. The infrared spectra of these oxocopper(II) complexes are interpreted and demonstrate that each of the complexes belong to the C 2 v symmetry. All bands related to v (CuO), as well as those characteristic of the coordinated water in each complex, are assigned.

Vibrational analysis of the trigonal bipyramidal NbCl5 and NbBr5 molecules

Abstract Vibrational normal coordinate analysis has been made for NbCl5 and NbBr5 molecules with D3h symmetry and using Wilsons GF matrix method. The observed frequencies are quantitatively assigned on the basis of the calculated potential energy distribution values for each vibration. The values of force constants for NbCl′ (axial) and NbCl (equatorial) bonds in NbCl5 equal 194 and 261 Nm−1, respectively. The corresponding values for NbBr5 are 142 and 217 Nm−1. These values are discussed in view of the bonding and structure of both compounds.