共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
Maria Lalia-Kantouri Christos D. Papadopoulos Antonios G. Hatzidimitriou Stavroula Skoulika 《Structural chemistry》2009,20(2):177-184
The reaction of Fe(III) with the substituted salicylaldehydes [X-saloH, where X = 3-OCH3 (L 1 ), 5-CH3 (L 2 ), 5-Cl (L 3 ), 5-NO2 (L 4 )] led to the formation of four new iron(III) hetero-heptanuclear complexes (Fe–Na) under the general formula [Fe2(X-salo)8Νa5] · 3OH · zH2Ο. The two different coordination modes of the ligand, as well as the geometry around the metal ions were deduced by X-ray structure analysis of compound 1, [Fe2(3-OCH3-salo)8Νa5] · 3OH · 8H2Ο. The complexes have also been characterized by physicochemical and spectroscopic (IR, UV–Vis, Mössbauer) methods. 相似文献
8.
N. V. Podberezskaya V. A. Maksakov I. V. Slovokhotova S. P. Babailov A. V. Virovets V. P. Kirin 《Journal of Structural Chemistry》1999,40(6):914-925
The reaction of (μ-H)Os3μ-O2CC5H4Mn(CO)3(CO)10 with PPh3 in the presence of Me3NO gave mono- and disubstituted heterometallic complexes (μ-H)Os3μ-O2CC5H4Mn(CO)3(PPh3)(CO)9 and (μ-H)Os3μ-O2CC5H4Mn(CO)3 (PPh3)2(CO)8. Crystal structure determination was performed for three isomeric cluster complexes (μ-H)Os3μ-O2CC5H4Mn(CO)3(PPh3)2(CO)8, which are both geometrical and conformational isomers differing in color. The geometrical isomerism is due to the attachment
of the PPh3 group at different vertices of the Os3 triangle relative to the O2CC5H4Mn(CO)3 bridging ligand. The conform ational isomerism implies that the molecules have the same arrangement of ligands and differ
only in the values of bond angles between the planar fragments of the clusters. 相似文献
9.
Reza Ghiasi 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(10):1542-1548
The electronic structure and properties of Cr(CO)3(B3N3H6 ? n F n ) (n = 1?C3) complexes have been explored using hybrid density functional B3LYP theory. Calculations indicate B-fluorinated isomers are more stable, and less polarizable, than N-fluorinated isomers. The aromatic natures of the borazine rings have been analyzed by nucleus independent chemical shift (NICS). The atoms in molecules (AIM) analysis indicates that Cr-C and Cr-N bonds distance is well correlated with the electron density of critical point (??cp) in all species. 相似文献
10.
Peter Kircher Gottfried Huttner Laszlo Zsolnai Alexander Driess 《Angewandte Chemie (International ed. in English)》1998,37(12):1666-1668
A formally isoelectronic ( μ 3 -Sn) 2− ion replaces the μ3-O building block in the subvalent anion 1 , which is a derivative of the known cage compound [(μ3-OR)4(μ3-O)4Sn6]. Thus, compound 1 forms a link between oxo metal clusters and Zintl ions. [(μ3-OH)(μ3-O)3(OEt)3{(CO)5W}7Sn7]2− 1 相似文献
11.
Boronic acids, R–B(OH)2, play an important role in synthetic, biological, medicinal, and materials chemistry. This investigation compares the structure and bonding surrounding the boron atoms in the simple aliphatic boronic acids, R–B(OH)2 (R=H; NH2, OH, and F), and the analogous borinic acids, R–BH(OH). Geometry optimizations were performed using second-order Møller–Plesset perturbation theory (MP2) with the Dunning–Woon aug-cc-pVTZ, aug-cc-pVQZ, and aug-cc-pV5Z basis sets; single-point CCSD(FC)/aug-cc-pVTZ//MP2(FC)/aug-cc-pVTZ level calculations were used to generate a QCI density for natural bond orbital analyses of the bonding. The optimized boron–oxygen bond lengths for the X–B–Ot–H trans-branch of the endo-exo form of the boronic acids and for the X–B–O–H cis-branch of the boronic and borinic acids (X=N, O, and F, respectively) decrease as the electronegativity of X increases. The boron–oxygen bond lengths are generally longer in the endo-exo or anti forms of the boronic acids than in the corresponding borinic acids. NBO analyses suggest the boron–oxygen bond in H2BOH is a double bond; the boron–oxygen bonding in the remaining boronic and borinic acids in this study has a significant contribution from dative pπ–pπ bonding. Values for Δ\({\text{H}}_{298}^{0}\) for the highly balanced reaction, R–B(OH)2 + R–BH2 → 2 R–BH(OH), suggest that the bonding surrounding the boron atom is stronger in the borinic acid than in the corresponding boronic acid. 相似文献
12.
《Journal of Coordination Chemistry》2012,65(9):1528-1543
Density functional theory calculations, with an effective core potential for the copper ion, and large polarized basis set functions have been used to construct the potential energy surface of the Cu+·(CO)n (n = 1–3) complexes. A linear configuration is obtained for the global minimum of the Cu+·CO and Cu+·(CO)2 complexes with a bond dissociation energy (BDE) of 35.9 and 40.0 kcal mol-1, respectively. For the Cu+·(CO)3 complex, a trigonal planar geometry is obtained for the global minimum with a BDE of 16.5 kcal mol?1. C-coordinated copper ion complexes exhibit stronger binding energy than O-coordinated complexes as a result of Clp → 4s σ-donation. The computed sequential BDEs of Cu+·(CO)n (n = 1–4) complexes agree well with experimental findings, in which the electrostatic energy and σ-donation play an important role in the observed trend. 相似文献
13.
14.
《Journal of organometallic chemistry》1994,464(1):71-76
The reaction of Cr(CO)3(NH3)3 with diphenylacetylene affords as a main product the complex with Cr(CO)3 moiety bound to a phenyl ring of diphenylacetylene; Cr(CO)3(η6-PhC2Ph) (I). Complex I readily reacts with Co2(CO)8 yielding the mixed metal complex Cr(CO)3(η6:η2-PhC2Ph)Co2(CO)6 (II). The reaction proceeds with retention of the Cr(CO)3 (η6-arene) structural unit, the Co2(CO)6 fragment being bound to the triple bond of diphenylacetylene in μ2,η2-mode. The structure of II was determined by single crystal X-ray analysis. The complex crystallizes in space group P21/c with unit cell parameters a 8.666(3) Å, b 18.046(3) Å, c 15.155(6) Å. β 97.57(3)°, V 2349(2) Å3, Z = 4, Dx = 1.70 g/cm3. The structure was solved by direct methods and refined by full-matrix least-squares technique to R and Rw values of 0.032 and 0.034, respectively, for 3655 observed reflections. The data obtained show that two structural units in II, Cr(CO)3(η6-Ph-) and Co2(CO)6(μ2,η2-CC), are distorted due to steric repulsion between these metal carbonyl moieties. The Cr(CO)3 fragment is shifted from the centre of the phenyl ring and slightly tilted with respect to the phenyl ring plane. The Co2C2 tetrahedron in the Co2(CO)6(μ2,η2-CC) moiety is distorted in such a way that two of the four CoiCj bonds are elongated. 相似文献
15.
16.
17.
《Journal of organometallic chemistry》1987,326(1):89-92
Investigation of π-(CH3nC5H5–nMn(CO)3 (Men-CpMnT) n = 0−5 and t-butyl CpMnT mass spectra showed that MenCpMnT molecular ion (M+) fragmentation occurs by a simpler scheme than that for MenCpReT M+ molecular ions. The reason is that MnCp and MnCO bonds are not as strong as the ReCp and ReCO bonds, and the relative “inertness” (compared to Re) of the Mn atom (ion), coordinated to the methylcyclopentadienyl ligand. Variations of M+ molecular ion intensity with different values of n are probably due to a complexity of electronic and spatial methyl-carbonyl group interactions in M+. 相似文献
18.
《Journal of organometallic chemistry》1987,319(2):167-181
The complex (η5-C5H5)NiRu3(μ-H)3(CO)9 catalyses the selective hydrogenation of the terminal double bond of conjugated linear dienes in homogeneous conditions; isomerization of non-conjugated to conjugated dienes and of pent-1-ene to pent-2-enes also occurs. Selective hydrogenation and isomerization of cyclic hexenes and hexadienes takes place without opening of the ring; a reaction scheme is proposed, and the activity of the cluster itself relative to that of its decomposition products is discussed. Its behaviour is compared with the analogous complex (η5-C5H5)NiOs3(μ-H)3(CO)9. 相似文献
19.
Structural Chemistry - Boronic acids, R–B(OH)2, play an important role in synthetic, biological, medicinal, and materials chemistry. Borinic acids, R–BH(OH), find relevance in similar... 相似文献
20.
《Journal of organometallic chemistry》1994,481(1):125-135
σ-Alkyl complexes of V(I) of the general composition (alkyl)V(CO)6−n pm have been prepared by UV-induced insertion of alkenes into the V-H bond of HV(CO)6−n pm, pm is an oligophosphine coordinating through n phosphorus functions. Spectroscopic characteristics (IR and multinuclear NMR) suggest that the structure in solution is a face-capped octahedron, as for the hydrido complexes. Many new hydrido complexes and their anionic ([V(CO)6−n pm]−) precursor compounds are also described. The crystal and molecular structures of trans-[V(CO)2(dppe)2], which forms as a byproduct in a side reaction of the photo-induced hydride transfer, have been determined. The compound crystallizes in the orthorhombic space group P22121 with the following cell parameters: a = 1220.4(2), b = 1421.5(3) and c = 1758.1(3) pm. 相似文献