共查询到20条相似文献,搜索用时 31 毫秒
1.
J. A. K. Tareen A. R. Fazeli B. Basavalingu G. T. Bhandige 《Journal of Thermal Analysis and Calorimetry》1995,44(4):937-954
Decarbonation curve for the synthetic dolomite analogues; (Cd-dolomites) were determined for CdMg(CO3)2, CdMn(CO3)2 and CdZn(CO3)2 under CO2 pressure of up to 2.5 kbar. All the three double carbonates were completely disordered at the decomposition temperatures and hence the thermodynamic data (Standard enthalpy; ΔH f o, Standard free energy; ΔG f o) retrieved from the univariant decarbonation curve corresponds to the disordered phases. They are: The mixing enthalpies and free energies for the formation of the disordered 1∶1 solid solution phases are: The thermodynamic data (ΔH f o, ΔG f o and ΔH r o, ΔG r o) showed a positive correlation with the decomposition temperatures. The mixing energies of the disordered double carbonates also show a direct correlation with the cationic size differences. 相似文献
2.
《Journal of organometallic chemistry》1987,329(3):349-355
The electrochemical reduction of (benzophenone)Cr(CO)3 and (benzophenone)[Cr(CO)3]2 in hthe presence of a series of alkyl chlorides which are more difficult to reduce, has been carried out in N,N-dimethylformamide on a mercury pool cathode. When methyl chloride and p-cyanobenzyl chloride are used as alkylating agents, complexed monoalkylated ethers are exclusively obtained as substitution products, in yields ranging from 36 to 54%. Complexed alkylated alcohols aer isolated as the major products when (benzophenone)Cr(CO)3 is reduced in the presence of benzyl-chloride and its 2,3,5-trimethyl derivative, in 48 and 44% yields, respectively. These last results suggest the intermediate formation of a charge transfer complex between the aromatic ring of the electrophile and the complexed ketone. 相似文献
3.
4.
The cyano carbonyl complexes [(99)Tc(CN)(3)(CO)(3)]2- and [Re(CN)(3)(CO)(3)]2- were synthesized and fully characterized. These complexes are additional members of the well-known d(6) transition metal complex series [M(CN)(3)(CO)(3)](n-). The analytical data obtained in this study thus offer a unique opportunity to study similarities and differences of cyanide and carbonyl binding in transition metal complexes. 相似文献
5.
Portius P Yang J Sun XZ Grills DC Matousek P Parker AW Towrie M George MW 《Journal of the American Chemical Society》2004,126(34):10713-10720
The photochemistry of Fe(CO)5 (5) has been studied in heptane, supercritical (sc) Ar, scXe, and scCH4 using time-resolved infrared spectroscopy (TRIR). 3Fe(CO)4 ((3)4) and Fe(CO)3(solvent) (3) are formed as primary photoproducts within the first few picoseconds. Complex 3 is formed via a single-photon process. In heptane, scCH4, and scXe, (3)4 decays to form (1)4 x L (L = heptane, CH4, or Xe) as well as reacting with 5 to form Fe2(CO)9. In heptane, 3 reacts with CO to form (1)4 x L. The conversion of (3)4 to (1)4 x L has been monitored directly for the first time (L = heptane, kobs = 7.8(+/- 0.3) x 10(7) s(-1); scCH4, 5(+/- 1) x 10(6) s(-1); scXe, 2.1(+/- 0.1) x 10(7) s(-1)). In scAr, (3)4 and 3 react with CO to form 5 and (3)4, respectively. We have determined the rate constant (kCO = 1.2 x 10(7) dm3 mol(-1) s(-1)) for the reaction of (3)4 with CO in scAr, and this is very similar to the value obtained previously in the gas phase. Doping the scAr with either Xe or CH4 resulted in (3)4 reacting with Xe or CH4 to form (1)4 x Xe or (1)4 x CH4. The relative yield, [(3)4]:[3] decreases in the order heptane > scXe > scCH4 > scAr, and pressure-dependent measurements in scAr and scCH4 indicate an influence of the solvent density on this ratio. 相似文献
6.
Gas phase infrared spectroscopic investigations of the CO vibration of jet-cooled NiCO, Ni(CO)3(13CO), and Ni(CO)3(C18O) are reported. The spectra were obtained using a recently assembled pulsed-discharge slit-jet IR diode laser spectrometer. The rotationally resolved spectrum of NiCO was collected as it was formed in the discharge, while the spectra of Ni(CO)3(13CO) and Ni(CO)3(C18O) were recorded as they were destroyed. For NiCO, band origins of 2010.692 89(34) and 2010.645 28(23) cm(-1) were measured, along with values of B0=0.151 094(7) and 0.149 597(6) cm(-1) and B(1)=0.150 244(7) and 0.148 742(6) cm(-1) for 58NiCO and 60NiCO, respectively. The B0 values for these isotopologs were used to determine the two bond lengths in NiCO, giving r0 (Ni-C)=1.641(40) A and r0 (C-O)=1.193(53) A, in agreement with recent microwave measurements. The constants determined for Ni(CO)3(13CO) were upsilon0=2022.075 753(95) cm(-1), B"=0.034 736(2) cm(-1), and B'=0.034 688(2) cm(-1). For Ni(CO)3(C18O), upsilon0=2021.936 83(18) cm(-1), B"=0.033 764(4) cm(-1), and B'=0.033 710(4) cm(-1) were obtained. From these rotational constants, bond lengths of r0 (Ni-C)=1.839+/-0.007 A and r0 (C-O)=1.121+/-0.010 A were obtained. These values are discussed in relation to the bond lengths measured by electron and x-ray diffraction methods. 相似文献
7.
《Journal of Coordination Chemistry》2012,65(1-2):145-149
Abstract Halogen atom transfer from CpMo(CO)3X (X = Cl, Br and I) to CpW(CO)3 ? forming CpMo(CO)3 ? and CpW(CO)3X occurs with a first-order dependence on the oxidant and the reductant. The rate constants show a very small dependence on the identity of X, suggesting a mechanism involving nucleophilic attack by CpW(CO)3 ? on a carbonyl of CpMo(CO)3X. 相似文献
8.
Pd (CO) (PPh3)3 could be isolated from the reaction mixture arising from cyclohexene hydrocarboxylation by PdCl2 (PPh3)2 as the catalyst precursor; furthermore, it has also been prepared through direct reaction of Pd (PPh3)4 with CO in benzene. For this complex, 31P- and 13C-NMR. spectra suggest a rapid dissociation of PPh3 at room temperature and a tetrahedral structure at – 70° in solution. 相似文献
9.
10.
Design and Syntheses of Three Novel Carbonate Halides: Cs3Pb2(CO3)3I,KBa2(CO3)2F,and RbBa2(CO3)2F
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lili Liu Dr. Yun Yang Dr. Xiaoyu Dong Bingbing Zhang Dr. Ying Wang Prof. Zhihua Yang Prof. Shilie Pan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(9):2944-2954
Three new carbonate halides, Cs3Pb2(CO3)3I, KBa2(CO3)2F and RbBa2(CO3)2F have been synthesized with hydrothermal and solid‐state methods. Cs3Pb2(CO3)3I is the first product in the lead carbonate iodides family; KBa2(CO3)2F and RbBa2(CO3)2F are the first two centrosymmetric compounds found in the alkaline–alkaline earth carbonate fluorides family. Cs3Pb2(CO3)3I crystallizes in a centrosymmetric space group C2/m, and exhibits a two‐ dimensional layered structure which is formed by [Cs4Pb4(CO3)6I2]∞ double‐layers consisting of [Pb2(CO3)3I]∞ single‐layers bridged by the Cs atoms. KBa2(CO3)2F and RbBa2(CO3)2F, which are isostructural, crystallize in a trigonal crystal system with a centric space group of R featuring a honeycomb‐like framework. First principle calculations indicate that Cs3Pb2(CO3)3I has a moderate birefringence and explain the difference between the band gaps of the title compounds from electron structures. The effects of cations and halogens on the structures and properties of the title compounds are also discussed. 相似文献
11.
Dr. Chaoxian Chi Dr. Jia-Qi Wang Hui Qu Wan-Lu Li Dr. Luyan Meng Prof. Mingbiao Luo Prof. Dr. Jun Li Prof. Dr. Mingfei Zhou 《Angewandte Chemie (International ed. in English)》2017,56(24):6932-6936
We report the preparation of UFe(CO)3− and OUFe(CO)3− complexes using a laser-vaporization supersonic ion source in the gas phase. These compounds were mass-selected and characterized by infrared photodissociation spectroscopy and state-of-the-art quantum chemical studies. There are unprecedented triple bonds between U 6d/5f and Fe 3d orbitals, featuring one covalent σ bond and two Fe-to-U dative π bonds in both complexes. The uranium and iron elements are found to exist in unique formal U(I or III) and Fe(−II) oxidation states, respectively. These findings suggest that there may exist a whole family of stable df–d multiple-bonded f-element-transition-metal compounds that have not been fully recognized to date. 相似文献
12.
A. N. Nesmeyanov E. G. Perevalova L. I. Leont'eva E. V. Shumilina 《Russian Chemical Bulletin》1977,26(12):2603-2605
Conclusions The photochemical reactions of (CO)2(PPh3)MnC5H4Fe(CO)2C5H5 and (CO)2(PPh3)MnC5H4COFe(CO)2C5H5 with PPh3 gave the products of replacing the CO on the Fe atom by PPh3: respectively (CO)2(PPh3)MnC5H4Fe (CO)(PPh3)C5H5 and (CO)2(PPh3)MnC5H4COFe(CO)(PPh3)C5H5.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2813–2815, December, 1977. 相似文献
13.
用银配合物制备均匀球形AgI纳米粒子,粒径20~100 nm范围内可自由调控.用AgI作为内置核,在尿素存在下,将Y(NO3)3进行升温水解,在预置粒子上包覆Y(OH)CO3形成复合粒子,并符合表面膜机理.结合X射线、电镜照片,考察了Y(NO3)3、尿素、银配合物、内置核的浓度,反应时间,水解温度,表面电荷对反应体系的影响.并加入配合剂Na2S2O3,运用生成稳定配合物的方法溶解内置核,最终得到Y(OH)CO3中空粒子. 相似文献
14.
本文报道Co-Ru簇的合成与表征的研究。由Et4N[RuCl4(CH3CN)2]和Co2(CO)8制备了Et4N[Co3Ru(CO)12]·1/3THF, 它与等摩尔的NOBF4反应得到Co3Ru(CO)11(NO)(1)和Co2Ru(CO)11(5)。簇合物1分别与乙炔、苯基乙炔和二苯基乙炔进一步反应得到(HC≡CH)Co3Ru(CO)9(NO)(2), (PhC≡CH)Co3Ru(CO)9(NO)(3)和(PhC≡CPh)Co3Ru(CO)9(NO)(4)。在上述反应中还分离得到(HC≡CH)Co2Ru(CO)9(6), (PhC≡CH)Co2Ru(CO)9(7)和(PhC≡CPh)Co2Ru(CO)9(8)。对所得族合物1,2,3,4进行了IR, UV,^1H NMR, m.p., 元素分析和单晶X射线衍射分析等性质表征, 簇合物3的晶体属单斜晶系, pα1/n空间群, 晶胞参数为: a=1.1438(9), b=.3033(6), c=1.4345(9)nm, β=100.72(4)°, 每个晶胞中有四个分子。 相似文献
15.
铬的羰基络合物及其碳炔衍生物中铬原子的共价 总被引:2,自引:0,他引:2
用DV-Xα方法和自然轨道法研究了Cr(CO)_6和(CO)_4ICrCCH_3的电子结构和成键情况,并根据共价新定义讨论了其中铬原子的共价。结果表明:在(CO)_4ICrCCH_3中,Cr-C_(carbyne)之间存在三重键,但其中只有σ键定域在Cr-C_(carbyne)两原子之间,而两个π键已部分离域到各CO上;另外,中心铬原子上的价电子未能反馈到C_(carbyne)上。两个因素同时作用,结果使C_(carbyne)上的电荷密度较同一分子中的C_(CO)和C_(Me)小.这一计算结果从理论上解释了该分子的~(13)CNMR谱化学位移C_(carbyne)大于C_(CO)和C_(Me)的原因。由于在Cr(CO)_6和(CO)_4ICrCCH_3分子中铬原子均接受了12个有效共享成键电子,根据共价新定义,铬原子共价均为12。 相似文献
16.
Fluorination of [Os(3)CO(12)] in HF/SbF(5) affords [Os(CO)(4)(FSbF(5))(2)]. According to its crystal structure (orthorhombic, Pna2(1), a = 1590.3(3), b = 1036.6(1), c = 878.2(2) pm, Z = 4), the two SbF(6) units occupy cis positions in the octahedral environment around the Os atom. Fluorination of [Ir(4)(CO)(12)] in HF/SbF(5) produced three different compounds: (1) [Ir(4)(CO)(8)(mu-F)(2)(Sb(2)F(11))(2)] (tetragonal, P4n2, a = 1285.2(2), c = 952.9(1) pm, Z = 2). Here, two of the six edges of the Ir(4) tetrahedron in [Ir(4)CO(12)] are replaced by bridging fluorine atoms. (2) [fac-Ir(CO)(3)(FSbF(5))(2)HF]SbF(6).HF (orthorhombic, Pnma, a = 1250.6(1), b = 1340.7(2), c = 1092.6(2) ppm, Z = 4). The Ir(4) tetrahedron in Ir(4)(CO)(12) is completely broken down, but the facial Ir(CO)(3) configuration is retained. (3) [mer-Ir(CO)(3)F(FSbF(5))(2)] (triclinic, P1, a = 834.9(1), b = 86 4.9(1), c = 1060.0(1) pm, alpha = 69.173(4) degrees, beta = 77.139(4) degrees, gamma = 88.856(4) degrees, Z = 2). 相似文献
17.
《Journal of organometallic chemistry》1987,323(1):C10-C12
[Ru(CO)4PMe3] reacts with MeI to give fac-[Ru(CO)3(PMe3)(Me)I]. The latter reacts with PMe3 to give a mixture of the three isomers of cis-bis(trimethylphosphine)-cis-dicarbonyl acetyl iodide [Ru(CO)2(PMe3)2(COMe)I]. Decarbonylation of the mixture gives only the trans-bis(trimethylphosphine)-cis-dicarbonyl methyl iodide complex [Ru(CO)2(PMe3)2MeI], which was also prepared by oxidative addition of MeI to [Ru(CO)3(PMe3)2]. 相似文献
18.
Brian F.G. Johnson David A. Kaner Jack Lewis Paul R. Raithby 《Journal of organometallic chemistry》1981,215(2):C33-C37
The reaction of [HOs3(CO)11]? with AuClPR3 (R Et, Ph) yields the complex HOs3Au(CO)10(PR3), and the PPh3 derivative has been characterised by an X-ray analysis; the structure is compared with that of Os3Au(CO)10(PPh3)-(SCN) and is shown to contain a formally unsaturated OsOs bond. 相似文献
19.
The results of kinetic studies on ligand substitution in [M3(CO)11X]– complexes (M = Ru, Os; X = Cl, Br, I) are summarized. The [Os3(CO)11X]– complexes react with PPh3 under mild conditions to initially yield monosubstituted products [Os3(CO)10(PPh3)X]–. The rate of CO substitution obeys a first-order equation with respect to the concentration of the complex and does not depend on the ligand concentration. The rates of the reactions decrease in the order Cl > Br > I withH values increasing from 15 to 18 kcal mol–1 and S
values varying from –19 to –13 cal mol–1 K–1. The enhanced reactivities of these complexes as well as the low activation energies and negative activation entropies are discussed in terms of the effects of -X bridge formation on the transition state of the reaction. Reactions of PPN[Ru3(CO)11–x
(Cl)] (PPN is the bis(triphenylphosphine)iminium cation;x=0, 1) and PPN[Ru3(CO)9(3-I)] with alkynes are also reported. The reactivities of alkynes follow the order BuCCH PhCCH EtCCEt PhCCPh. The higher rates of the reactions of monosubstituted acetylenes compared with those of their disubstituted analogs are explained by agostic interaction between the metal atom and the C-H bond in the reaction transition state and by steric effects. The results obtained attest that the reaction with alkynes occursvia intermediates containing halide bridges and that 3-halide complexes are more reactive than 2-halide complexes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1540–1545, September, 1994.This work was supported by a Presidential Grant from Northwestern University. One of the authors (F. Basolo) wishes to thank Academician M. E. Vol'pin for the invitation to participate in the Workshop The Modern Problems of Organometallic Chemistry (INEOS-94) and Academician O. M. Nefedov for the invitation to publish a review in theRussian Chemical Bulletin. 相似文献