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1.
C–H?N and C–H?S hydrogen bonds were analyzed in complexes where acetylene, ethylene, methane and their derivatives are proton donors while ammonia and hydrogen sulfide are proton acceptors. Ab initio calculations were performed to analyze those interactions; MP2 method was applied and the following basis sets were used: 6-311++G(d,p), aug-cc-pVDZ and aug-cc-pVTZ. The results showed that hydrogen bonds for complexes with ammonia are systematically stronger than such interactions in complexes with hydrogen sulfide. If the fluorine substituted hydrocarbons are considered then F-substituents enhance the strength of hydrogen bonding. For a few complexes, mainly those where carbon atom in proton donating C–H bond possesses sp3 hybridization, the blue-shifting hydrogen bonds were detected. Additionally, Quantum Theory of ‘Atoms in Molecules’ and Natural Bond Orbitals method were applied to analyze H-bond interactions.  相似文献   

2.
The synthesis and X-ray structural characterization of two silver(I) coordination polymers, [Ag2(bpp)2(Phdac)]·5H2O (1) and [Ag2(bpp)(HSSal)] (2), are reported, where bpp = 4,4′-trimethylene dipyridine, H2Phdac = 1,4-phenylenediacetic acid, and H3SSal = 5-sulfosalicylic acid. X-ray crystallography reveals that the structures are stabilized through hydrogen bonding interactions. The C–H?π and metal?π interactions of aromatic molecules play a crucial role in building a layered framework. Intricate combinations of the weak non-covalent interactions have been analyzed to explore cooperativity and competitiveness in the solid-state structures.  相似文献   

3.
Quantum chemistry calculations at the density functional theory (DFT) (B3LYP), MP2, QCISD, QCISD(T), and CCSD(T) levels in conjunction with 6-311++G(2d,2p) and 6-311++G(2df,2p) basis sets have been performed to explore the binding energies of open-shell hydrogen bonded complexes formed between the HOCO radical (both cis-HOCO and trans-HOCO) and trans-HCOOH (formic acid), H(2)SO(4) (sulfuric acid), and cis-cis-H(2)CO(3) (carbonic acid). Calculations at the CCSD(T)∕6-311++G(2df,2p) level predict that these open-shell complexes have relatively large binding energies ranging between 9.4 to 13.5 kcal∕mol and that cis-HOCO (cH) binds more strongly compared to trans-HOCO in these complexes. The zero-point-energy-corrected binding strengths of the cH?Acid complexes are comparable to that of the formic acid homodimer complex (~13-14 kcal∕mol). Infrared fundamental frequencies and intensities of the complexes are computed within the harmonic approximation. Infrared spectroscopy is suggested as a potential useful tool for detection of these HOCO?Acid complexes in the laboratory as well as in various planetary atmospheres since complex formation is found to induce large frequency shifts and intensity enhancement of the H-bonded OH stretching fundamental relative to that of the corresponding parent monomers. Finally, the ability of an acid molecule such as formic acid to catalyze the inter-conversion between the cis- and trans-HOCO isomers in the gas phase is also discussed.  相似文献   

4.
5.
An efficient approach toward C–H bond activation using iodine-mediated sp3C–H bond functionalization for the synthesis of dialkyl 3-(quinolin-2-yl)indolizine-1,2-dicarboxylates and dialkyl 3-(quinolin-2-yl)pyrrolo[2,1-a]isoquinoline-1,2-dicarboxylates through 1,3-dipolar cycloaddition reaction of nitrogen ylides with acetylenic esters is described.  相似文献   

6.
A simple ammonium iodide salt in amide solvent catalyzes regioselective decarboxylative alkylation of C(sp~3)-H bonds of Naryl glycine derivatives, of C(sp~2)-H bond of heteroarenes, and cascade radical addition to unsaturated bond followed by intramolecular addition to arene, with a broad scope of N-hydroxyphthalimide derived redox active esters under visible light irradiation. The reactions are suggested to proceed through photoactivation of a transiently assembled chromophore from electron-deficient phthalimide moiety and iodide anion through an anion-π interaction in solvent cage followed by diffusion to generate solvated free radical species to react with C-H substrates. The simplicity, practicality, and broad substrate scope of this method highlight the synthetic power of photocatalysis through transiently assembled chromophore, and will hopefully inspire further developments of low cost photocatalysis based on various non-covalent interactions, which are prevalent in supramolecular chemistry and biosystems, for sustainable organic synthesis.  相似文献   

7.
The salt Rb[C6H3(COO)2()] · [C6H3(COOH)3] · 2H2O (I) of trimesic acid was synthesized and its thermal stability and conductivity (10–11 ohm–1 cm–1 at 298 K) were measured. Molecular and crystal structures of I were established by X-ray diffraction analysis. Hydrogen bonding system in complex I was detected by IR and Raman spectroscopies. X-ray diffraction data agree with vibration spectroscopy data.  相似文献   

8.
The characteristics and structures of single-electron halogen bond complexes [H3C?Br-Y (Y = H, CCH, CN, NC, C2H3)] have been investigated by theoretical calculation methods. The geometries were optimized and frequencies calculated at the B3LYP/6-311++G** level. The interaction energies were corrected for basis set superposition error (BSSE) and the wavefunctions obtained by the natural bond orbital (NBO) and atom in molecule (AIM) analyses at the MP2/6-311++G** level. For each H3C?Br-Y complex, a single-electron Br bond is formed between the unpaired electron of the CH3 (electron donor) radical and the Br atom of Br-Y (electron acceptor); this kind of single-electron bromine bond also possesses the character of a “three-electron bond”. Due to the formation of the single-electron Br bond, the C-H bonds of the CH3 radical bend away from the Br-Y moiety and the Br-Y bond elongates, giving red-shifted single-electron Br bond complexes. The effects of substituents, hybridization of the carbon atom, and solvent on the properties of the complexes have been investigated. The strengths of single-electron hydrogen bonds, single-electron halogen bonds and single-electron lithium bonds have been compared. In addition, the single-electron halogen bond system is discussed in the light of the first three criteria for hydrogen bonding proposed by Popelier.  相似文献   

9.
The bis(cyclopropylammonium)dihydrogenodiphosphate monohydrate is a new diphosphate associated with the organic molecule C3H5NH2. We report the chemical preparation and the crystal structure of this organic cation diphosphate. (C3H5NH3)2H2P2O7.H2O is orthorhombic (S.G. : P212121), with Z = 4 and the following unit-cell parameters : a = 4.828(1) Å, b = 11.011(1) Å, c = 25.645(2) Å. The P2O7 groups and H2O water molecules form a succession of bidimensional layers perpendicular to the c axis. The organic cations ensure the three-dimensional cohesion by NH-O hydrogen bonds.  相似文献   

10.
《Fluid Phase Equilibria》1999,165(2):157-168
A simple method is developed to estimate mixture critical temperatures (Tc), pressures (Pc), and densities (ρc) as a function of overall composition (X) from near critical region experimental coexistence data. This three-step method is applied to four mixtures, CO2–C3H8, CO2nC4H10, C2H6–C3H8, and C3H8nC4H10. Isothermal liquid–vapor coexistence data, which includes temperature, vapor pressure, coexisting densities (ρ and ρv), and coexisting compositions for the more volatile component (x1v and x1) are used. In the first step, the difference of the saturated liquid and vapor densities (ρρv) is fitted to an empirical function in ((PcP)/Pc) to obtain Pc. Then P/Pc and ((ρ+ρv)/2ρc) are simultaneously fitted to functions of a polynomial in (X1−(x1v+x1)/2) yielding estimates of ρc and X1. Finally, the discrete estimated critical data points are fitted with an equation to provide a continuous representation of the critical lines. The method is successfully tested for the mixtures, CO2–C3H8 and CO2nC4H10, for which there is a reasonable amount of isothermal data. The procedure is then applied to the mixtures, C2H6–C3H8 and C3H8nC4H10, for which there are sparse data. For all four mixtures, the critical temperature line, Tc vs. X1, matches literature values within ±0.5%. The critical pressure line, Pc vs. X1, and critical density line, ρc vs. X1, match literature values, in general, within ±2%.  相似文献   

11.
Reactions of a solution of AgNO3 in aqueous methanol with solutions of 1,4-diallylpiperazine (acidified with HNO3 to pH = 4) and 1-allyloxybenzotriazole in ethanol gave the crystalline silver(I) π-complexes [Ag2(C4H8N2(C3H5)2(H+)2)(H2O)2(NO3)2](NO3)2 (I) and [Ag(C6H4N3(OC3H5)(NO3))] (II). Their crystal structures were determined by X-ray diffraction. Crystals of complexes I and II are monoclinic, space group P21/c; for I: a = 7.053(3)Å, b = 9.389(3)Å, c = 15.488(4)Å, β = 91.60°, V = 1025.3(6)Å3, Z = 4; for II: a = 10.650(4)Å, b = 15.062(5)Å, c = 7.412(4)Å, β = 104.20(3)°, V = 1152.6(8)Å3, Z = 4. In both structures, the organic components act as bidentate ligands forming with AgNO3 34- and 14-membered topological rings, respectively. In complex I, the nearly tetrahedral environment of the Ag(I) atom is made up of the olefinic C=C bond, the O atoms of the nitrate anions, and the water molecule. 1-Allyloxybenzotriazole in structure II causes the deformation of the coordination polyhedron of Ag into a trigonal pyramid via inclusion of the ligand N atom in its coordination sphere. The topological units of the complexes form infinite polymer layers linked by anionic NO 3 ? bridges. In structure I, these layers are united through a system of hydrogen bonds into a three-dimensional framework.  相似文献   

12.
We carried out the crossed molecular beam reaction of ground state methylidyne radicals, CH(X(2)Π), with acetylene, C(2)H(2)(X(1)Σ(g)(+)), at a nominal collision energy of 16.8 kJ mol(-1). Under single collision conditions, we identified both the atomic and molecular hydrogen loss pathways forming C(3)H(2) and C(3)H isomers, respectively. A detailed analysis of the experimental data suggested the formation of c-C(3)H(2) (31.5 ± 5.0%), HCCCH/H(2)CCC (59.5 ± 5.0%), and l-HCCC (9.0 ± 2.0%). The reaction proceeded indirectly via complex formation and involved the unimolecular decomposition of long-lived propargyl radicals to form l-HCCC plus molecular hydrogen and HCCCH/H(2)CCC plus atomic hydrogen. The formation of c-C(3)H(2) was suggested to be produced via unimolecular decomposition of the cyclopropenyl radical, which in turn could be accessed via addition of the methylidyne radical to both carbon atoms of the acetylene molecule or after an initial addition to only one acetylenic carbon atom via ring closure. This investigation brings us closer to unraveling of the reaction of important combustion radicals-methylidyne-and the connected unimolecular decomposition of chemically activated propargyl radicals. This also links to the formation of C(3)H and C(3)H(2) in combustion flames and in the interstellar medium.  相似文献   

13.
Regioselective copper(I)-catalyzed C–H hydroxylation/C–S coupling of aryl thiols with vinyl halides was developed. Starting from substituted aryl thiols and vinyl halides, various 2-(styrylthio)phenol derivatives were efficiently prepared. The application of the synthetic methodology to generate the bioactive organic intermediate was also exemplified.  相似文献   

14.
The work deals with the establishment of the dependence of the vibrational frequencies of strong O–H?O and N–H?O hydrogen bonds for the diagnosing the bonds themselves. To this end, the Raman spectra of a large number of different normal and deutero-substituted crystals characterized by the presence of strong O–H?O and N–H?O bonds are measured and the quantum chemical calculation is performed for one of these compounds. The dependence of the O–H stretching frequency on the O?O distance is constructed differing from that previously known for short O?O contacts. The mechanisms of significant broadening of the O–H vibration band in strong O–H?O hydrogen bonds are considered. Different dependences of the N–H vibrational frequencies in N–H?O bonds are reported and the causes of this diversity are discussed.  相似文献   

15.
以三聚氰胺和硼酸为原料在水溶液中反应合成出了一种新的BCN化合物先驱体C3N6H6(H3BO3)2。XRD表征结果表明三聚氰胺和硼酸的最佳配比为1∶3(物质的量比)。用单晶X-射线衍射分析法测定了该化合物的晶体结构。该化合物属单斜晶系,空间群为P21/C,晶胞参数为a=0.3597(7)nm,b=2.0105(4)nm,c=1.4112(3)nm,α=90,°β=92.07(3),°γ=90,°V=1.0199(3)nm3,Z=4,D c=1.627g.cm-3,μ(MoKα)=0.144mm-1,F(000)=520。晶体结构经全矩阵最小二乘法修正,最终可靠因子R1=0.0519,wR2=0.1361。该化合物是由C3N6H6分子和H3BO3分子通过氢键加合组装形成的三维超分子结构化合物。  相似文献   

16.
X-ray diffraction study of tetranuclear organobismuth complexes Bi4(O)2(O2CC6H2F3-3,4,5)8 · 26-C6H6 and Bi4(O)2(O2CC6H2F3-3,4,5)8 · 2(C6H4Me2-1,4) revealed four Bi atoms connected through the bridging carboxylate ligands and the O atoms. The coordination sphere of the terminal Bi atoms includes the chelate carboxylate ligand and the 6-arene molecule. The bridging O atoms are tricoordinated, the distances between the terminal Bi atom and the center of benzene molecule (1,4-dimethylbenzene) are 3.024 Å(3.131 Å).Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 1, 2005, pp. 4–11.Original Russian Text Copyright © 2005 by Sharutin, Egorova, Sharutina, Ivanenko, Adonin, Starichenko, Pushilin, Gerasimenko.  相似文献   

17.
《Journal of Coordination Chemistry》2012,65(17-18):1545-1551
A new three-dimensional complex [Tm2(C5H3N(COO)2)3(H2O)3)]·H2O (PDC?=?3,5-pyridinedicarboxylate), has been synthesized and its structure determined by x-ray single crystal diffraction methods. Complex 1 crystallizes in the monoclinic space group P2(1)/n with a?=?14.579(4), b?=?11.193(3), c?=?14.839(5)?Å, β?=?94.009(6)°, U?=?2415.5(13)?Å3. Two independent PDC ligands bridge TmIII ions from different orientations to form a network. Thermogravimetric analyses on compound 1 show its high structural stability to 410°C.  相似文献   

18.
用水热法合成了3,5-二氨基苯甲酸与Nd(Ⅲ)的配合物Nd(C7H7N2O2)3(H2O)3(1),其结构经IR,元素分析和X-射线单晶衍射仪表征。1为单核结构,属六方晶系,R3空间群,晶胞参数:a=1.887 29(18)nm,b=1.887 29(18)nm,c=0.603 53(12)nm,β=90,°γ=120°,V=1.861 7(4)nm3,Z=3,μ=2.154 mm-1,Dc=1.744 g.cm-3,R1=0.014 3,wR2=0.033 2。1中Nd(Ⅲ)与来自3个3,5-二氨基苯甲酸的6个氧原子及3个配位水的氧原子进行配位,形成9配位化合物。  相似文献   

19.
The reaction of the ytterbium(II) bis(indenyl) complex (C9H7)2Yb(thf)2 (1) with 2,2’-bipyridine afforded the diamagnetic (C9H7)2Yb(bipy) compound (2), whose structure was established by X-ray diffraction analysis. Under similar conditions, the reaction of complex 1 with 1,4-bis(2,6-diisopropylphenyl)-1,4-diazabuta-1,3-diene (DAD) led to oxidation of ytterbium giving rise to the paramagnetic (C9H7)2Yb(DAD) complex (3). Magnetic measurements, X-ray diffraction study, and 1H NMR spectroscopy in benzene confirmed the trivalent state of the ytterbium atom and the radical-anionic nature of the diazadiene ligand in complex 3. In the complex 3—solvent system, the oxidation state of metal depends on the coordination ability of the solvent. In benzene, complex 3 exists as (C9H7)2YbIII(DAD·-), whereas (C9H7)2YbII(thf)2 and DAD0 are present in THF.  相似文献   

20.
The ??-complexes [CuCl(C3H5NHC2H4CN)] (I), [(C3H5NH2C2H4CN)Cu2Cl3] (II), [((C3H5)2NHC2H4CN)CuCl2] (III), and [((C3H5)2NHC2H4CN)CuBr2] (IV) are obtained as single crystals by the ac electrochemical synthesis on copper wire electrodes from ethanolic solutions of 3-(allylamino)propanenitrile, 3-(diallylamino)propanenitrile, and CuX2 (X = Cl, Br). Their crystal structures are determined. The crystals of compounds I, III, and IV are monoclinic, space group P21/c, Z = 4. The crystals of compound II are triclinic, space group P $\bar 1$ , Z = 2. The unit cell parameters are a = 11.125(4), b = 8.769(4), c = 8.570(4) ?, ?? = 90.94(4)°, V = 835.9(6) ?3 (I); a = 6.2566(4), b = 7.5975(6), c = 11.1251(8) ?, ?? = 90.896(6)°, ?? = 92.827(5)°, ?? = 94.340(5)°, V = 526.57(7) ?3 (II); a = 11.656(4), b = 6.992(4), c = 14.681(5) ?, ?? = 100.89(4)°, V = 1174.9(9) ?3 (III); a =11.845(4), b = 7.282(4), c=14.855(5) ?, ?? = 100.37(4)°, V = 1260.4(9) ?3 (IV). The coordination mode of the Cu(I) atom in complex I includes two halogen atoms, the C=C bond, and the secondary amine N atom. The coordination environment in isostructural crystals of complexes III and IV is formed by the C=C bond and three halogen atoms as in complex II.  相似文献   

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