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1.
应用考虑重叠修正项多重散身Xα自洽场方法,详细研究其重叠修正项对过渡金属配合物分子的价电子轨道的影响,进一步利用不可约张量方法,发展一种求解多体Schrodinger方程的方法. 将该方法应用于计算Cr(CN) ,Co(CN) , COF 的d-d跃迁能,其结果优于其它理论方法的计算结果.计算结果还表明Xα方法中重叠修正项对多体问题有一定的影响.  相似文献   

2.
应用考虑重叠修正项多重散身Xα自洽场方法,详细研究其重叠修正项对过渡金属配合物分子的价电子轨道的影响,进一步利用不可约张量方法,发展一种求解多体Schrodinger方程的方法. 将该方法应用于计算Cr(CN) ,Co(CN) , COF 的d-d跃迁能,其结果优于其它理论方法的计算结果.计算结果还表明Xα方法中重叠修正项对多体问题有一定的影响.  相似文献   

3.
Bis(4‐picoline‐κN)gold(I) dibromidoaurate(I), [Au(C6H7N)2][AuBr2], (I), crystallizes in the monoclinic space group P21/n, with two half cations and one general anion in the asymmetric unit. The cations, located on centres of inversion, assemble to form chains parallel to the a axis, but there are no significant contacts between the cations. Cohesion is provided by flanking anions, which are connected to the cations by short Au...Au contacts and C—H...Br hydrogen bonds, and to each other by Br...Br contacts. The corresponding chloride derivative, [Au(C6H7N)2][AuCl2], (II), is isotypic. A previous structure determination of (II), reported in the space group P with very similar axis lengths to those of (I) [Lin et al. (2008). Inorg. Chem. 47 , 2543–2551], might be identical to the structure presented here, except that its γ angle of 88.79 (7)° seems to rule out a monoclinic cell. No phase transformation of (II) could be detected on the basis of data sets recorded at 100, 200 and 295 K.  相似文献   

4.
A new series of platinum(II) complexes with tridentate ligands 2,6‐bis(1‐alkyl‐1,2,3‐triazol‐4‐yl)pyridine and 2,6‐bis(1‐aryl‐1,2,3‐triazol‐4‐yl)pyridine (N7R), [Pt(N7R)Cl]X ( 1 – 7 ) and [Pt(N7R)(C?CR′)]X ( 8 – 17 ; R=n‐C4H9, n‐C8H17, n‐C12H25, n‐C14H29, n‐C18H37, C6H5, and CH2‐C6H5; R′=C6H5, C6H4‐CH3p, C6H4‐CF3p, C6H4‐N(CH3)2p, and cholesteryl 2‐propyn‐1‐yl carbonate; X=OTf?, PF6?, and Cl?), has been synthesized and characterized. Their electrochemical and photophysical properties have also been studied. Two amphiphilic platinum(II)? 2,6‐bis(1‐dodecyl‐1,2,3‐triazol‐4‐yl)pyridine complexes ( 3‐Cl and 8 ) were found to form stable and reproducible Langmuir–Blodgett (LB) films at the air/water interface. These LB films were characterized by the study of their surface‐pressure–molecular‐area (π–A) isotherms, XRD, and IR and polarized‐IR spectroscopy.  相似文献   

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6.
A novel single‐electron sodium bond system of H3C···Na? H (I), H3C···Na? OH(II), H3C···Na? F(III), H3C···Na‐CCH(IV), H3C···Na? CN (V) and H3C···Na? NC (VI) complexes has been studied by using MP2/6‐311++G** and MP2/aug‐cc‐pVTZ methods for the first time. We demonstrated that the single‐electron sodium bond H3C···Na? Y formed between H3C and Na? Y (Y?H, OH, F, CCH, CN, and NC) could induce the Na? Y increased and stretching frequencies of I–IV and VI are red‐shifted, including the Na? N bond in complex V is blue‐shifted abnormally. The interaction energies are calculated at two levels of theory [MP2, CCSD(T)] with different basis. The results shows that the strength of binding bond in group 2 (IV–VI) with π electrons are stronger than that of group 1 (I–III) without π electrons. For all complexes, the main orbital interactions between moieties H3C and Na? Y are LP1(C)→LP*1(Na). By comparisons with some related systems, it is concluded that the strength of single‐electron bond is increased in the order: hydrogen bond < bromine bond < sodium bond < lithium bond. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011  相似文献   

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From the systems Cu(II)–cyclam–[M(CN)4]2? (cyclam = 1,4,8,11-tetraazacyclotetradecane; M = Ni, Pd, Pt), three cyanidocomplexes Cu(cyclam)M(CN)4 [M = Ni (1), Pd (2), Pt (3)] were isolated and characterized by chemical analysis, IR and UV–VIS spectroscopy. The three compounds are isostructural, and their crystal structures are formed by quasi-linear chains exhibiting [–Cu(cyclam)–μ–NC–M(CN)2–μ–CN–]n composition. The Cu(II) atoms reside on centres of symmetry and are coordinated in the form of an elongated octahedron with mean equatorial Cu–N bonds of 2.015(12), 2.017(13) and 2.011(11) Å in (1), (2) and (3), respectively, and weakly N-bonded bridging cyanido ligands in the axial positions [2.5321(9) Å in (1), 2.518(2) Å in (2) and 2.549(3) Å in (3)]. Hydrogen bonds of the N–H···Ncyanido···H–N type link neighbouring chains, and a topologically square network of paramagnetic Cu(II) atoms is formed. The magnetic susceptibilities of all three complexes follow the Curie-Weiss law with a weak antiferromagnetic exchange coupling below 5 K.  相似文献   

9.
Energy-transfer reaction from metastable CO(a~3П) molecule to CN radical has been studied in a room-temperature flow reactor. The CN (B-X, △v=0, ±1, ±2) violet emission bands were obtained. The △v=0 sequence of CN(B) were analyzed by computer simulation. The vibrational temperature is 3400 K. By using the reference reaction CO(a)+NO, the formation rate constant of CN(B) has been measured, k_(CN)(B)=1.1×10~(-11) cm~3·molecule~(-1)·s~(-1).  相似文献   

10.
Three new salts of tetrahedral rhenium chalcocyanide cluster anions [Re4Q4(CN)12]4? (Q = S, Se, Te) and 1,10-phenanthroline-1-ium cations, (phenH)4[Re4S4(CN)12]·6H2O (1), (phenH)4[Re4Se4(CN)12]·6H2O (2), and (phenH)4[Re4Te4(CN)12]·10H2O (3), have been synthesized by reactions of K4[Re4Q4(CN)12nH2O with 1,10-phenanthroline in the presence of Nd3+ in an acidic aqueous medium (pH 4). 1 and 2 exhibit similar 2-D layered supramolecular architectures based on hydrogen bonds between water molecules, CN-groups of cluster anions, and phenH+ cations. The latter are involved in ππ and C–H?π stacking interactions, connecting the adjacent layers with each other. Complex 3 demonstrates a 3-D framework based on hydrogen bonds between water molecules and CN-groups, ππ and C–H?π interactions. Notably short O···Te contacts of 3.40 and 3.50 Å are found in the structure of 3. The thermal properties of 1–3 have been investigated by TG-DTG.  相似文献   

11.
Binary complex salts, [Co(En)3][Fe(CN)6] · 2H2O and [Co(En)3]4[Fe(CN)6]3 · 15H2O, are synthesized. The properties of the salts and their thermolysis in air, dihydrogen, and argon are studied. Oxides of the central ions of the binary complex salts are found to be the thermolysis products in an oxidative atmosphere. Solid solutions (intermetallic compounds) CoFe are the thermolysis products in the reductive atmosphere, whereas intermetallides containing considerable amounts of C and N and an impurity of Co and Fe oxides are the thermolysis products in an inert atmosphere. Gaseous thermolysis products in dihydrogen and argon are NH3, hydrocarbons, and ethylenediamine.  相似文献   

12.
The title complexes [μ‐(E)‐4,4′‐(ethene‐1,2‐diyl)­di­pyridine‐κ2N:N′]­bis­[halotris(4‐methyl­phenyl)­tin(IV)], [Sn2(C7H7)6X2(C12H10N2)], where halo is chloro (X = Cl) and bromo (X = Br) are isostructural. In both crystals, the mol­ecules lie on inversion centers, and there are voids of ca 80 Å3 that could, but apparently do not, accommodate water mol­ecules. The corresponding iodo structure (X = I) is almost, but not quite, isostructural with the other two compounds; when Br is changed to I, the length of the c axis decreases by more than 1 Å and the voids are no longer large enough to accomodate any solvent mol­ecule. The related complex [μ‐(E)‐4,4′‐(ethene‐1,2‐diyl)­di­pyridine‐κ2N:N′]­bis­[chloro­tri­phenyl­tin(IV)], [Sn2(C6H5)6Cl2(C12H10N2)], crystallizes in a related structure, but the mol­ecules lie on general rather than on special positions. The molecular structures of the four complexes are similar, but the conformation of the phenyl derivative is approximately eclipsed rather than staggered.  相似文献   

13.
A series of poly(ε‐caprolactone) (PCL)‐based multiblock poly(ether‐ester)s (PEE)s and poly(ether‐ester‐amide)s (PEEA)s were obtained from α,ω‐dihydroxy‐PCL ( = 2–4 kDa) and ? COCl di‐terminated poly(ethylene oxide) (PEO) macromers (MAC) of different length ( = 150, 300, 600, 1 000 Da). 4,7,10‐Trioxa‐1,13‐tridecanediamine was used in the synthesis of PEEAs. Bulk polycondensation processes were accomplished by one step (PEE) and two step (PEEA) procedures. PEEAs with PCL/MAC/Trioxy molar ratios 1:2:1 and 1:3:2 were investigated. The multiblock copolymer architecture was proved by 1H NMR and size exclusion chromatography (SEC) techniques. Unimodal molecular weight (MW) distributions and values in the range of 13.3–21.0 kDa (PEE) and 8.1–12.8 kDa (PEEA) were found. Crystalline PCL‐type phases were identified for both PEEAs and PEEs by X‐ray diffraction. The thermal transitions were investigated by differential scanning calorimetry (DSC). The Tm values (49.9–53.4 °C) reflect those of the PCL component while the Tg of PEEAs (?45 to ?52 °C) are higher than those of the PEEs (?58 to ?61 °C) or the macromers. The equilibrium water uptakes range from 1.0 to 18.4 wt.‐% (PEE) and from 4.4 to 8.8 wt.‐% (PEEA) depending on both the composition and length of the ethylene oxide sequences. A dependence of surface homogeneity on copolymer composition was found for PEEs by dynamic contact angle measurements.

The preparation of PEEAs and PEEs.  相似文献   


14.
《Solid State Sciences》2000,2(6):607-614
We have investigated the crystal structures of CsLnFe(CN)6·nH2O (Ln=lanthanide, n=4,5), as well as TlTmRu(CN)6·3H2O. These phases can be thought of as derivatives of LnFe(CN)6·4H2O, where, simultaneously, an alkali ion (or Tl+) is introduced while the valence of Fe is reduced from Fe3+ to Fe2+. A new arrangement of the structural units is observed in the CsLnFe(CN)6·5H2O, where the coordination of the Ln-ion is changed to a bisdisphenoid. The resulting LnN5O3 units alternate with Fe(CN)6 units to form an overall rocksalt-type ralted lattice that accommodates the alkali ions in interstitial sites. Due to the arrangement of the water molecules, a layer structure results.  相似文献   

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Single crystals of Cu(bapen)Ni(CN)4·H2O and Cu(bapen)Pd(CN)4·H2O (bapen = N,N′-bis(3-aminopropyl)-1,2-diaminoethane) were isolated from the aqueous systems copper(II)—bapen—[M(CN)4]2? (M = Ni, Pd). Crystals of the two compounds are isostructural and are built up of two crystallographically independent quasi-linear chains [-Cu(bapen)-μ2-NC-Ni(CN)22-CN-] n and solvate water molecules. The copper(II) centers exhibit the usual distorted octahedral coordination with one tetradentate bapen ligand in the equatorial plane (mean Cu–N are 2.030 Å for Cu(bapen)Ni(CN)4·H2O and 2.018 Å for Cu(bapen)Pd(CN)4·H2O), while the axial positions are occupied by nitrogen atoms from μ2-bridging cyanido ligands with longer Cu–N bonds (mean values are 2.544 Å for Cu(bapen)Ni(CN)4·H2O and 2.543 Å for Cu(bapen)Pd(CN)4·H2O). One of the two independent coordinated bapen ligands is disordered, as are the water molecules of crystallization. The Ni and Pd atoms in both studied compounds exhibit the usual square coordination with the bridging cyanido ligands trans to each other. Several OH···O, N–H···O and N–H···N hydrogen bonds enhance the stability of the structures. ESR spectra corroborated the presence of Jahn–Teller anisotropy at the copper(II) atoms. Magnetic studies in the temperature range 1.8–300 K reveal that both Cu(bapen)Ni(CN)4·H2O and Cu(bapen)Pd(CN)4·H2O follow Curie-Weiss laws with θ = ?0.51 K and θ = ?0.34 K, respectively, suggesting the presence of weak antiferromagnetic interactions.  相似文献   

18.
A new and efficient synthesis of 2‐[1‐alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic acid derivatives by a one‐pot three‐component reaction between primary amine, dialkyl acetylenedicarboxylate, and itaconic anhydride (=3,4‐dihydro‐3‐methylidenefuran‐2,5‐dione) is reported. The reaction was performed without catalyst and under solvent‐free conditions with excellent yields. Notably, the ready availability of the starting materials, and the high level of practicability of the reaction and workup make this approach an attractive complementary method to access to unknown 2‐[1‐alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic acid derivatives. The structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of domino Michael addition? cyclization reaction is proposed (Scheme 2).  相似文献   

19.
Analysis and modeling of X-ray and neutron Bragg and total diffraction data show that the compounds referred to in the literature as "Pd(CN)(2)" and "Pt(CN)(2)" are nanocrystalline materials containing small sheets of vertex-sharing square-planar M(CN)(4) units, layered in a disordered manner with an intersheet separation of ~3.44 ? at 300 K. The small size of the crystallites means that the sheets' edges form a significant fraction of each material. The Pd(CN)(2) nanocrystallites studied using total neutron diffraction are terminated by water and the Pt(CN)(2) nanocrystallites by ammonia, in place of half of the terminal cyanide groups, thus maintaining charge neutrality. The neutron samples contain sheets of approximate dimensions 30 ? × 30 ?. For sheets of the size we describe, our structural models predict compositions of Pd(CN)(2)·xH(2)O and Pt(CN)(2)·yNH(3) (x ≈ y ≈ 0.29). These values are in good agreement with those obtained from total neutron diffraction and thermal analysis, and are also supported by infrared and Raman spectroscopy measurements. It is also possible to prepare related compounds Pd(CN)(2)·pNH(3) and Pt(CN)(2)·qH(2)O, in which the terminating groups are exchanged. Additional samples showing sheet sizes in the range ~10 ? × 10 ? (y ~ 0.67) to ~80 ? × 80 ? (p = q ~ 0.12), as determined by X-ray diffraction, have been prepared. The related mixed-metal phase, Pd(1/2)Pt(1/2)(CN)(2)·qH(2)O (q ~ 0.50), is also nanocrystalline (sheet size ~15 ? × 15 ?). In all cases, the interiors of the sheets are isostructural with those found in Ni(CN)(2). Removal of the final traces of water or ammonia by heating results in decomposition of the compounds to Pd and Pt metal, or in the case of the mixed-metal cyanide, the alloy, Pd(1/2)Pt(1/2), making it impossible to prepare the simple cyanides, Pd(CN)(2), Pt(CN)(2), or Pd(1/2)Pt(1/2)(CN)(2), by this method.  相似文献   

20.
A series of isostructural Ln3O2(CN3) (Ln=La, Eu, Gd, Tb, Ho, Yb) oxoguanidinates was synthesized under high-pressure (25–54 GPa) high-temperature (2000–3000 K) conditions in laser-heated diamond anvil cells. The crystal structure of this novel class of compounds was determined via synchrotron single-crystal X-ray diffraction (SCXRD) as well as corroborated by X-ray absorption near edge structure (XANES) measurements and density functional theory (DFT) calculations. The Ln3O2(CN3) solids are composed of the hitherto unknown CN35− guanidinate anion—deprotonated guanidine. Changes in unit cell volumes and compressibility of Ln3O2(CN3) (Ln=La, Eu, Gd, Tb, Ho, Yb) compounds are found to be dictated by the lanthanide contraction phenomenon. Decompression experiments show that Ln3O2(CN3) compounds are recoverable to ambient conditions. The stabilization of the CN35− guanidinate anion at ambient conditions provides new opportunities in inorganic and organic synthetic chemistry.  相似文献   

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