排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
Marija Vojnovi Draan Jozi Gerald Giester Berislav Peri Pavica Planini Nevenka Brni
evi 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):m219-m220
The novel title compound, [(CH3)4N]2[Ta6Br12(H2O)6]Br4·2H2O, with a [Ta6Br12]2+ cluster unit, has been prepared and structurally characterized. The compound crystallizes in space group C2/c, with a twofold axis passing through the cluster and the centre of symmetry located between the clusters. The nearest neighbouring cluster units are aligned along the crystallographic c axis, forming a one‐dimensional chain pattern. 相似文献
2.
Marija Vojnovi Berislav Peri Pavica Planini Gerald Giester Nevenka Brni
evi 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):i71-i73
The title compound, [Ta6Br12(H2O)6](Br0.4Cl1.6)·8H2O, crystallizes in space group P. The structure contains two crystallographically independent [Ta6Br12(H2O)6]2+ cluster cations forming distinct layers parallel to the ab plane. The compound is isoconfigurational with the double salts [Ta6Br12(H2O)6]X2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O (X = Cl, Br). 相似文献
3.
Berislav Peri Draan Jozi Pavica Planini Nevenka Brni
evi Gerald Giester 《Journal of solid state chemistry》2009,182(9):2443-2450
A new hexanuclear cluster compound, [Et4N][Ta6Br12(H2O)6]Br4·4H2O (Et=ethyl) (1), with the paramagnetic [Ta6Br12]3+ cluster entity, was synthesized and characterized by elemental and TG/DTA analyses, IR and UV/Vis spectroscopy and by a single-crystal X-ray diffraction study. The presence of the paramagnetic [Ta6Br12]3+ unit was confirmed also by the room-temperature magnetic and EPR measurements. The compound crystallizes in the tetragonal I41/a space group, with a=14.299(5), c=21.241(5) Å, Z=4, R1(F)/wR2(F2)=0.0296/0.0811. The structure contains discrete [Ta6Br12(H2O)6]3+ cations with an octahedron of metal atoms edge-bridged by bromine atoms and with water molecules occupying all six terminal positions. The cluster units are positioned in the vertices of the three-dimensional (pseudo)diamond lattice. The structure shows similarities with literature reported structures of cluster compounds crystallizing in the diamond space group. 相似文献
4.
5.
A new synthesis of Mo2(CO)8(-PPh2)2 and W2(CO)8(-PPh2)2 by the reaction of molybdenum and tungsten hexacarbonyls with a tetraazamacrocyclic ligand containing —CH2PPh2 side chains, comprising cleavage of the phosphorus-methylene bond has been performed. The complexes have been investigated by magnetic and spectroscopic measurements and by single-crystal structure analyses. The structural characterization of a new polymorph of Mo2(CO)8(-PPh2)2 has been described. 相似文献
6.
Lidija Andro Pavica Planini Marijana Juri 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(9):o337-o340
The asymmetric unit of the title compound, C10H10N22+·2C2HO4−, consists of one half of a 4,4′‐bipyridinium cation, which has inversion symmetry, and a hydrogen oxalate anion, in which an intramolecular hydrogen bond exists. The cations and anions are connected by O—H...O, N—H...O and C—H...O hydrogen bonds, forming a two‐dimensional network, whereas π–π stacking interactions involving the 4,4′‐bipyridinium cations lead to the formation of a three‐dimensional supramolecular structure. An unusual deca‐atomic ring is formed between two hydrogen oxalate anions, which are linked side‐to‐side via O—H...O hydrogen‐bonding interactions. 相似文献
7.
Marijana??estan Berislav?Peri? Gerald?Giester Pavica?Planini? Nevenka?Brni?evi?Email author 《Structural chemistry》2005,16(4):409-414
The compound Rb3[NbO(C2O4)3]⋅2H2O (1) has been synthesized by two different methods and its exact chemical composition established. The niobium atom is heptacoordinated by oxygen atoms forming a distorted pentagonal bipyramid. Inspite of some similarities, the structure of 1 is not isotypic with the structure of (NH4)3[NbO(C2O4)3]⋅H2O. 相似文献
8.
Marija Vojnovi Draan Jozi Ivan Baic Sanda Ron
evi Pavica Planini 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):m33-m34
The title compound, (C4H12N)4[Ta6Cl18]Cl, crystallizes in the cubic space group . The crystal structure contains two different types of coordination polyhedra, i.e. four tetrahedral [(CH3)4N]+ cations and one octahedral [(Ta6Cl12)Cl6]3− cluster anion, and one Cl− ion. The presence of three different kinds of Cl atoms [bridging (μ2), terminal and counter‐anion] in one molecule makes this substance unique in the chemistry of hexanuclear halide clusters of niobium and tantalum. The Ta6 octahedron has an ideal Oh symmetry, with a Ta—Ta interatomic distance of 2.9215 (7) Å. 相似文献
9.
Marijana Jurić Berislav Perić Nevenka Brničević Pavica Planinić Damir Pajić Krešo Zadro Gerald Giester 《Polyhedron》2007
Two novel compounds of the formulae [{Cu(phen)2}2(μ-C2O4)][Cu(phen)2(μ-C2O4)NbO(C2O4)2]2 · 8H2O (1) and [{Cu(bpy)2}2(μ-C2O4)][Cu(bpy)2(μ-C2O4)NbO(C2O4)2]2 · 0.5bpy · 7H2O (2) (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine) have been prepared and characterized by single crystal X-ray diffraction, IR spectroscopy and magnetic susceptibility measurements. The molecular structure of both 1 and 2 consists of a discrete CuIICuII oxalate-bridged dinuclear [{Cu(L)2}2(μ-C2O4)]2+ cation (A unit) and two CuIINbV oxalate-bridged dinuclear [Cu(L)2(μ-C2O4)NbO(C2O4)2]− anions (B units) (L = phen, bpy). In 1 a crystallographic inversion centre is located in the middle of the oxalate bridge of the A unit, whereas in 2 an analogous inversion centre is missing. In the A units the copper(II) atoms adopt a tetragonally elongated octahedral coordination with the equatorial planes being perpendicular to the mean planes of the oxalate bridge and parallel to each other. In both structures, similar one-dimensional motifs are generated through the ligand stacking interactions, with a difference that one free bipyridine molecule, present in 2, intercalates into one of the motifs. It is shown that the phenanthroline ligand, due to its ability of stacking through the central aromatic ring, causes longer intermolecular Cu?Cu distances than the bipyridine ligand. The magnetic susceptibility measurements (1.8–290 K) show the ferromagnetic exchange interaction between the copper(II) atoms in the A units of both compounds, with J = +5.9 cm−1 and +7.9 cm−1 for 1 and 2, respectively (J – the exchange parameter in the isotropic spin Hamiltonian HINT = −JS1 · S2). 相似文献
10.
Pavica Planinić Vesna Rastija Siniša Širac Marija Vojnović Leo Frkanec Nevenka Brničević Robert E. McCarley 《Journal of Cluster Science》2002,13(2):215-222
Three new series of mixed-ligand clusters of the [(M6X12)X2(RCN)4] (M=Nb, Ta; X=Cl, Br; R=Et, n-Pr, n-Bu) composition have been prepared. It is supposed that four nitrile molecules and two halogen atoms are coordinated to the terminal octahedral coordination sites of the [M6X12]2+ unit. 相似文献