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1.
The molecular geometries, vibrational properties, and thermodynamic properties of the clusters (Cl2GaN3)n(n=1–4) have been predicted at the B3LYP/6‐311+G* level. The optimized clusters (Cl2GaN3)n (n=2–4) all possess cyclic structures containing Ga Nα Ga linkages. The relationships between geometrical parameters and oligomerization degree n are discussed. The gas‐phase structures of the trimers prefer to exist in boat‐twisting conformation. As for the tetramer, the S4 symmetry structure is the most stable. The infrared spectra are obtained and assigned by vibrational analysis. Thermodynamic properties derived from the infrared spectra on the basis of statistical thermodynamic principles are linearly correlated with the oligomerization degree n as well as the temperature. Meanwhile, thermodynamic analysis of the gas‐phase reaction suggests that the oligomerization is exothermic and favorable under high temperature. 相似文献
2.
Ying Fu Yin‐Xia He Hong‐Xia Hou Wen‐Bo Zhu Hu‐Lin Li Chao Wu Fang‐Yan Xian 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(3):282-284
2,2′‐Anhydro‐1‐(3′,5′‐di‐O‐acetyl‐β‐D‐arabinofuranosyl)uracil, C13H14N2O7, was obtained by refluxing 2′,3′‐O‐(methoxymethylene)uridine in acetic anhydride. The structure exhibits a nearly perfect C4′‐endo (4E) conformation. The best four‐atom plane of the five‐membered furanose ring is O—C—C—C, involving the C atoms of the fused five‐membered oxazolidine ring, and the torsion angle is only −0.4 (2)°. The oxazolidine ring is essentially coplanar with the six‐membered uracil ring [r.m.s. deviation = 0.012 (5) Å and dihedral angle = −3.2 (3)°]. The conformation at the exocyclic C—C bond is gauche–trans which is stabilized by various C—H...π and C—O...π interactions. 相似文献
3.
1,4‐Di(isopropyl)‐1,4‐diazabutadiene as a Reagent for the Trapping of Monomeric Fragments of the Tetragalliumcluster Ga4[C(SiMe3)3]4 – Formation of an Unsaturated GaN2C2 Heterocycle and an Oxidation Product Containing a Ga‐O‐O‐Ga Group The tetrahedral tetragallium cluster Ga4[C(SiMe3)3]4 ( 1 ) dissociates upon dissolution to yield the monomeric fragments Ga‐R [R = C(SiMe3)3]. These monomers could be trapped now by the treatment of their solutions with 1,4‐di(isopropyl)‐1,4‐diazabutadiene. The product of the cycloaddition reaction ( 2 ) possesses a five‐membered GaN2C2 heterocycle with a coordinatively unsaturated gallium atom and an endocyclic C=C double bond. 2 is rather sensitive towards oxidation by traces of air. The contact with oxygen yielded a digallium peroxide [(C2N2iPr2)RGa‐O‐O‐GaR(C2N2iPr2)] ( 3 ) which was isolated in a very low yield only and which has a gallium atom attached to each oxygen atom of the inner peroxo group. Both chelating ligands of 3 possess an unpaired electron. 相似文献
4.
Sang Woo Cho Yongkee Cho Dae‐Kee Kim Whanchul Shin 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):653-654
In the title compound, [Pt(C3H2O4)(C7H16N2O2)], the Pt atom is coordinated to two O and two N atoms in a square‐planar arrangement. The two independent molecules, which have very similar structures, are approximately related by pseudo‐twofold screw‐axis symmetry. The six‐membered chelate ring in the leaving ligand assumes a conformation intermediate between the half‐chair and boat forms. The seven‐membered ring in the carrier ligand assumes a twist‐chair conformation and the oxolane ring assumes an envelope conformation. The crystal packing consists of extensive hydrogen‐bonding networks which form two‐dimensional molecular layers, and there are weak van der Waals interactions between these layers. 相似文献
5.
J. Zukerman‐Schpector Mauricio Vega I. Caracelli Luiz C. Dias Anna M. A. P. Fernandes 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1089-1091
In 6‐methyl‐N‐(4‐nitrobenzoyl)‐5,6‐dihydropyridin‐2(1H)‐one, C13H12N2O4, (I), the piperidone ring is in a distorted half‐chair conformation. In 8‐methoxy‐3‐methyl‐N‐(4‐nitrobenzoyl)‐1,2,3,4,5,6,7,8‐octahydroisoquinoline‐1,6‐dione, C18H20N2O6, (II), the heterocyclic ring is in a slightly distorted half‐boat conformation, while the other six‐membered ring is in a distorted chair conformation. Compound (II) presents a strong intramolecular C—H?O hydrogen bond. In both (I) and (II), the molecules interact through C—H?O interactions. 相似文献
6.
Ana María Atria Gino Corsini Maria Teresa Garland Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(11):m342-m345
In the title polymeric compound, [Cu(C9H6O4)(C3H4N2)2]n, the copper(II) cation occupies an N2O3 coordination sphere defined by two 1H‐imidazole (imid) ligands in trans positions and three carboxylate O atoms from three different 2‐(carboxylatomethyl)benzoate (hpt2−) dianions. The geometry is that of a square pyramid with one of the O atoms at the apex, bridging neighbouring metal centres into an [–ON2CuO2CuN2O–] dinuclear unit. These units are in turn connected by hpt anions into a reticular mesh topologically characterized by two types of loops, viz. a four‐membered Cu2O2 diamond motif and a 32‐membered Cu4O8C20 ring. The imid groups do not take part in the formation of the two‐dimensional structure, but take part in the N—H...O interactions. These arise only within individual planes, interplanar interactions being only of the van der Waals type. 相似文献
7.
A new neutral anion receptor – macrocyclic octalactam 2 , possessing a large 36‐membered ring, was synthesized, and its unusual property of encapsulation of two Cl− ions and two H2O molecules in the cavity was confirmed by X‐ray crystallography (see Figure). The octalactam, consisting of four 2,6‐dicarbamoylpyridine and four ethylene moieties, exhibits a symmetrical, fully expanded conformation in the complex [(Cl)2( 2 )(H2O)2]2− (obtained as 2 ⋅2 Bu4NCl⋅4 H2O⋅2 CH2Cl2). Inside the cavity, encapsulated species – two Cl− ions and two H2O molecules – are connected to each other by H‐bonds. This kind of complex‐in‐complex system is formed by means of twenty intra‐ring H‐bonds and additionally four from the ‘outside' H2O molecules. Considering size and symmetry, it can be stated that the planar (H2O⋅Cl−)2 dimer fits well into the cavity of octalactam 2 . The ligand has an optimal arrangement of binding sites to form H‐bonds to every corner of the dimer. 相似文献
8.
Giuseppe Bruno Francesco Nicol Giuseppe Tresoldi 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):282-283
The title compound, [Ru(NO2)2(OH)(C10H8N2S)(NO)], is the main product of the reaction between RuCl3 and dps (dps is 2,2′‐dipyridyl sulfide, C10H8N2S) in ethanol–water at room temperature followed by reaction with NaNO2 at a higher temperature. The Ru atom has a distorted octahedral coordination geometry with the dps molecule behaving as an N,N′‐bidentate ligand. The six‐membered chelate ring adopts a boat conformation. 相似文献
9.
Introduction The organoaluminum azide compounds have been widely used in many fields. These compounds are used as the azidating agents,1-3 and the energetic materials which are always used in national defence industry and in space technology, especially to generate thin films of AlN in various chemical vapor deposition (CVD) sys-tems.4-6 Aluminum nitride has useful properties for coatings, especially for optical or optoelectronic devices, acoustic wave devices and electronic microcircuits.7 … 相似文献
10.
Jana Maderov Jaromír Marek Frantiek Pavel
ík 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):m178-m180
The mononuclear title complex, [Co(C6H6NO6)(C2H8N2)]·3H2O, contains an octahedrally coordinated CoIII atom. The N‐(carboxymethyl)aspartate moiety is coordinated as a tetradentate ligand, providing an OONO‐donor set and forming two trans five‐membered chelate rings and one six‐membered chelate ring. A seven‐membered chelate ring is also formed, which consists of part of the six‐membered chelate ring and part of one of the five‐membered chelate rings. The crystal structure of the complex is stabilized by hydrogen bonds with three water molecules. 相似文献
11.
Ahmet Bulut Hasan budak Gzde Sezer Canan Kazak 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(5):m228-m230
In the crystal structure of the title compound, bis(2‐aminopyrimidine‐κN1)bis[6‐methyl‐1,2,3‐oxathiazin‐4(3H)‐one 2,2‐dioxide(1−)‐κ2N3,O4]copper(II), [Cu(C4H4NO4S)2(C4H5N3)2], the first mixed‐ligand complex of acesulfame, the CuII centre resides on a centre of symmetry and has an octahedral geometry that is distorted both by the presence of four‐membered chelate rings and by the Jahn–Teller effect. The equatorial plane is formed by the N atoms of two aminopyrimidine (ampym) ligands and by the weakly basic carbonyl O atoms of the acesulfamate ligands, while the more basic deprotonated N atoms of these ligands are in the elongated axial positions with a strong misdirected valence. The crystal is stabilized by pyrimidine ring stacking and by intermolecular hydrogen bonding involving the NH2 moiety of the ampym ligand and the carbonyl O atom of the acesulfamate moiety. 相似文献
12.
Chi Chen Chang‐Wei Su Chun‐Wei Yeh Hui‐Ling Hu Jhy‐Der Chen Ju‐Chun Wang 《中国化学会会志》2006,53(2):299-303
The reaction of N,N′‐di(2‐pyridyl)formamidine (HDpyF) with MnCl2‐4H2O afforded the complex MnCl2(HDpyF), which was characterized by X‐ray crystallography. The HDpyF ligand chelates to the Mn(II) center through the first and the third nitrogen atoms to form a six‐membered ring, leaving the second and the fourth nitrogen atoms uncoordinated. The HDpyF ligand is crystallographically disordered such that two different molecules can be solved. The neutral HDpyF ligand adopts the new s‐cis‐syn‐s‐trans conformation. 相似文献
13.
Gang Xue Wen Xu Wentao Yu Qi Fang 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):m27-m29
The title compound, (C7H10N)[Ni(C3S5)2] or (Etpy)[Ni(dmit)2] (where Etpy is the N‐ethylpyridinium cation, C7H10N+, and dmit is the 2‐thioxo‐1,3‐dithiole‐4,5‐dithiolate dianion, C3S52−), crystallizes in the P space group with two molecules in the asymmetric unit. The [Ni(dmit)2]− monoanion has a planar D2h conformation, with the central Ni atom and the four coordinated S atoms forming an NiS4 square plane. The six‐membered ring of the Etpy cation also shows good planarity, as expected. There are two main types of disorder in the two Etpy cations. Several short intermolecular interactions are present, such as S⋯S, Ni⋯S and Ni⋯Ni, which help to form the enhanced three‐dimensional structure of the crystal. 相似文献
14.
Wei Sun Yan‐Tuan Li Zhi‐Yong Wu Ning‐Yu Xiao 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):m111-m113
In the crystal structure of the title complex, [Ni2(C10H20N4O2)(C12H12N2)2](ClO4)2 or [Ni(dmaeoxd)Ni(dmbp)2](ClO4)2 {H2dmaeoxd is N,N′‐bis[2‐(dimethylamino)ethyl]oxamide and dmbp is 4,4′‐dimethyl‐2,2′‐bipyridine}, the deprotonated dmaeoxd2− ligand is in a cis conformation and bridges two NiII atoms, one of which is located in a slightly distorted square‐planar environment, while the other is in an irregular octahedral environment. The cation is located on a twofold symmetry axis running through both Ni atoms. The dmaeoxd2− ligands interact with each other via C—H⋯O hydrogen bonds and π–π interactions, which results in an extended chain along the c axis. 相似文献
15.
Baolong Li Baozong Li Xia Zhu Liming Zhu Yong Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(9):m350-m351
The coordination geometry of the ZnII atom in the title complex, [Zn(C2N3)2(C6H8N6)2]n or [Zn(dca)2(bte)2]n, where bte is μ‐1,2‐bis(1,2,4‐triazol‐1‐yl)ethane and dca is dicyanamide, is distorted compressed octahedral, in which the ZnII atom lies on an inversion center and coordinates four N atoms from the triazole rings of four symmetry‐related bte ligands and two N atoms from two symmetry‐related monodentate dca ligands. The structure is polymeric, with 18‐membered spiro‐fused rings extending in the b direction and each 18‐membered ring involving two inversion‐related bte molecules. 相似文献
16.
Kelly Flood Neil F. Curtis Ward T. Robinson 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(2):m78-m80
The title compound, [Co(NCS)2(C11H26N4)]2[Zn(NCS)4]·C2H5OH, has two similar cations with the CoIII atom coordinated in a planar fashion by the 13‐membered cyclic tetraamine, in the 1R,4S,7R,10S configuration, and with trans isothiocyanate ligands. The six‐membered chelate ring is in a chair conformation, with one axially and one equatorially oriented methyl substituent [mean Co—N = 1.948 (2) Å]. The `opposite' chelate ring (N4 and N7) is in an eclipsed conformation [mean Co—N = 1.928 (2) Å], and the `side' chelate rings have gauche conformations. The mean Co—NNCS distance is 1.928 (2) Å. Both cations have one Co—N—C group nearly linear and the other appreciably bent, with mean Co—N—C angles of 178.7 (1) and 160.4 (1)°, respectively. The [Zn(NCS)4]2− anion is approximately tetrahedral, with Zn—N = 1.951 (1)–1.986 (1) Å, N—Zn—N = 104.5 (1)–111.9 (1)° and Zn—N—C = 152.5 (1)–179.4 (1)°. One NH group is hydrogen bonded to the ethanol O atom and the other NH groups are bonded to thiocyanate S atoms, forming a network. 相似文献
17.
Frank Seela Yang He Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o194-o196
In the title compound, 3‐amino‐2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐6‐methyl‐1,2,4‐triazin‐5(2H)‐one, C9H14N4O4, the conformation of the N‐glycosidic bond is high‐anti and the 2‐deoxyribofuranosyl moiety adopts a North sugar pucker (2T3). The orientation of the exocyclic C—C bond between the –CH2OH group and the five‐membered ring is ap (gauche, trans). The crystal packing is such that the nucleobases lie parallel to the ac plane; the planes are connected via hydrogen bonds involving the five‐membered ring. 相似文献
18.
19.
Nam Sook Cho Soon Il Hong Jin‐Gyu Kim Il‐Hwan Suh 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):229-230
The title compound, C14H16N4O8S4, has crystallographic C2 symmetry with half a molecule in the asymmetric unit and a dihedral angle of 58.7 (1)° between the two planar 1,3,4‐thiadiazole five‐membered rings of the macrocyclic, giving the molecule a twisted conformation. 相似文献
20.
Gakuse Hoshina Masanobu Tsuchimoto Shigeru Ohba 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e122-e122
In crystals of the title compound, [Ni(C28H22N2O2)], the coordination geometry around the Ni atom is square planar with a slight tetrahedral distortion. The five‐membered N,N′‐chelate ring adopts a distorted gauche conformation with the two phenyl groups in axial and equatorial orientations. 相似文献