Distinctive features of the structure of hemihexaphyrazine complexes with Y, La, and Lu according to quantum chemical data

DFT Study of Molecular and Electronic Structure of Ca(II) and Zn(II) Complexes with Porphyrazine and tetrakis(1,2,5-thiadiazole)porphyrazine

“…As it was previously found for the complexes of La and Lu with hemihexaphyrazine [24], the perimeters of the internal 16-membered macrocycle of all the studied structures ( Figure 4…”

DFT Study of Molecular and Electronic Structure of Y, La and Lu Complexes with Porphyrazine and Tetrakis(1,2,5-thiadiazole)porphyrazine

“…The value of lanthanide contraction Δr Ln , which may be estimated as a difference between r(La-N p ) and r(Lu-N p ) distance values, is 0.202 Å for both MClPz and MClTTDPz. It should be noted that the obtained value of Δr Ln is close to similar theoretical value in the series of compounds with tridentate ligand (0.208 Å) [ 26 ], experimental values in the series of ML 3 with monovalent ligands, such as the series of trichlorides (0.186(8) Å), tribromides (0.185(8) Å) and triiodides (0.193(8) Å) [ 27 , 28 , 29 , 30 , 31 ], as well as in the series of compounds with bidentate ligands, for example, in the series of tris-dipivaloylmethanates (0.186(6) Å) [ 32 , 33 ]. The similarity of Δr Ln values in lanthanide compounds with three ligands and in complexes considered in the present study indicates that, with no regard of the size of the central atom in the lanthanide series, the geometric structure of the coordination cavity is adjusted to the size of the central atom with the formation of coordination bonds.…”

“…Similar tendencies in the change of the charges were revealed in the complexes MPz and MTTDPz with transition metals Ca, Fe, Co and Zn [ 17 , 23 ]. The charge on the metal atoms is about +2.2 e, which is comparable to the charge on the Y, La and Lu atoms in the tridentate macroheterocyclic ligand [ 26 ]. In the studied complexes the charge of a ligand varies from −1.447 to −1.362 e, and in complexes with transition metals from −1.580 to −1.141 e. In addition, the charges on the atoms of the internal macrocycle (C α , N p , N m ) are close to each other in the case of all the complexes considered (the complexes studied in this work and the complexes with transition metals [ 17 , 23 ]).…”

Vaporization Processes and Accurate Molecular Structure of a Number of Organic and Inorganic Compounds Promising for Use in Technologies Involving the Gas Phase

“…Структуры свободных молекул H2hp и H2dchp были определены методом газовой электронографии [19] Строение и энергетика гемигексафиразина, его металлокомплексов и тиадиазол-аннелированного гемигексафиразина Исследование строения молекул гемигексафиразина и его металлокомплексов, а также тиадиазол-аннелированного гемигексафиразина представлено в работах [21][22][23][24][25][26][27][28]. Эффузионным методом Кнудсена с масс-спектрометрическим контролем состава пара определена энтальпия сублимации незамещенного гемигексафиразина, которая составила 252(2) кДж/моль [21].…”

“…В работе [25] с помощью квантово-химических расчетов установлено, что в отличие от безметального гемигексафиразина, имеющего плоское строение, его комплексы с Y, La и Lu обладают неплоским строением макроцикла симметрии Cs, причем наименьшим искажением плоскости макроцикла обладает комплекс с лантаном, т.к. размер центрального атома наиболее соответствует размеру расширенной координационной полости данного лиганда.…”