Cs[VO 2 (NO 3 ) 2 ] ( I ), MoO 2 (NO 3 ) 2 ( II ), and Cs[MoO 2 (NO 3 ) 3 ] ( III ) complexes have been obtained by crystallization from nitric solutions and studied by single-crystal X-ray diffraction. Complexes I and II contain infinite zigzag chains of similar compositions, [VO 2 (NO 3 ) 2 ] − and [MoO 2 (NO 3 ) 2 ], in which V and Mo atoms form, respectively, trigonal- and pentagonal-bipyramidal polyhedra. Each of these polyhedrons also contains one terminal and two bridge O atoms and two terminal NO 3 groups which are monodentate and bidentate in complexes I and II , respectively. Complex III has an island structure and consists of Cs + cations and [MoO 2 (NO 3 ) 3 ] − anions, in which the Mo atom is surrounded by one bidentate NO 3 group and two monodentate NO 3 groups and two terminal O atoms in the cis -positions; oxygen atoms form a polyhedron in the form of distorted octahedron. According to the ab initio calculation of isolated MoO 2 (NO 3 ) 2 molecules in the gas phase and solution, the coordination environment of the Mo atom, similarly to the Cr( VI ) atom in CrO 2 (NO 3 ) 2 , is formed by two bidentate nitrate groups and two terminal O atoms (polyhedron- twisted trigonal prism).

Dissolution of vanadium in anhydrous HNO3 followed by exposure of the solution in a dessicator over P2O5 gave liquid vanadyl trinitrate (I). The X-ray diffraction analysis of I was carried out for a single crystal grown on cooling the liquid in a sealed capillary. The structure is composed of VO(NO)(3) molecules in which the V atom has an unusually high C.N. 7; it coordinates the terminal O atom and three bidentate nitrate groups to form a distorted pentagonal bipyramid as the coordination polyhedron with the terminal O atom occupying one axial vertex. Using the GAMESS program package, ab initio calculation of the structure of VO (NO3)(3) in the liquid phase was carried out. It was shown that in all three physical states, vanadyl trinitrate retains its molecular structure almost invariable. Toluene and naphthalene nitration using I and (NO2)[Fe(NO3)(4)], NO[Cu(NO3)(3)], (NO)(3/4)(NO2)(1/4)[Zr(NO3)(5)], and MoO2(NO3)(2) proceeds at high rates at low temperatures to give an unusually high para-nitrotoluene percentage in the products as compared with the ortho-isomer. The activity of the studied compounds in the nitration of naphthalene decreases in the series VO(NO3)(3) > (NO)(3/4)(NO2)(1/4)[Zr(NO3)(5)] > MoO2(NO3)(2).

Possibility of obtaining a 2,4-dinitrotoluene-enriched mixture of dinitrotoluenes in a single stage by nitration of toluene at 0°C with a mixture of nitric acid and phosphoric anhydride or metaphosphoric acid was examined.

Растворением ванадия в безводной HNO3 с последующим выдерживанием раствора в эксикаторе над P2O5 получен жидкий тринитрат ванадила VO(NO3)3 (I). Рентгеноструктурный анализ I выполнен на монокристалле, выращенном при охлаждении жидкости в герметичном капилляре. Структура I состоит из молекул VO(NO3)3, в которых атом V проявляет необычно высокое КЧ 7, координируя концевой атом О и три бидентатные нитратные группы с образованием координационного полиэдра в форме искаженной пентагональной бипирамиды, причем концевой атом О занимает одну из аксиальных вершин. С использованием программного комплекса GAMESS проведен неэмпирический расчет строения VO(NO3)3 в жидкой фазе. Показано, что во всех трех агрегатных состояниях тринитрат ванадила сохраняет почти неизменное молекулярное строение. Установлено, что нитрование толуола и нафталина с помощью I, а также (NO2)[Fe(NO3)4], NO[Cu(NO3)3], (NO)3/4(NO2)1/4[Zr(NO3)5] и MoO2(NO3)2 идет с высокой скоростью при низких температурах и приводит к необычно высокому содержанию в продуктах пара-нитротолуола по сравнению с орто-изомером. Активность изученных веществ в реакциях нитрования нафталина уменьшается в следующем ряду: VO(NO3)3 > (NO)3/4(NO2)1/4[Zr(NO3)5] > MoO2(NO3)2.

Cs[VO2(NO3)2] (I), MoO2(NO3)2 (II), and Cs[MoO2(NO3)3] (III) complexes have been obtained by crystallization from nitric solutions and studied by single crystal X ray diffraction. Complexes I and II contain infinite zigzag chains of similar compositions, [VO2(NO3)2] – and [MoO2(NO3)2], in which V and Mo atoms form, respectively, trigonal and pentagonal bipyramidal polyhedra. Each of these polyhe drons also contains one terminal and two bridge O atoms and two terminal NO3 groups which are monoden tate and bidentate in complexes I and II, respectively. Complex III has an island structure and consists of Cs+ cations and [MoO2(NO3)3] – anions, in which the Mo atom is surrounded by one bidentate NO3 group and two monodentate NO3 groups and two terminal O atoms in the cis positions; oxygen atoms form a polyhe dron in the form of distorted octahedron. According to the ab initio calculation of isolated MoO2(NO3)2 mol ecules in the gas phase and solution, the coordination environment of the Mo atom, similarly to the Cr(VI) atom in CrO2(NO3)2, is formed by two bidentate nitrate groups and two terminal O atoms (polyhedron– twisted trigonal prism). DOI: 10.1134/S1063774510030053