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1.
A new μ3-O triiron(III) complex [Fe3O(OBz)6(CH3OH)3](NO3)(CH3OH)2 (HOBZ = benzoic acid) has been synthesized, its structure has been determined and variable temperature magnetic susceptility has also been measured. In the molecule, three iron atoms formed an equilateral triangle with μ3-O in center. The fitting to the magnetic susceptibility showed that an intramolecular antiferromagnetic exchange interaction occurred between iron atoms with J=-25.51 cm?1, and a weaker intermolecular autiferromagnetic exchange interaction occurred with zJ' = ?2.30 cm?1.  相似文献   

2.
The magnetic property of μ3-oxotriiron(III) complex [Fe3O(OBz)6(CH3OH)3](NP3)-(CH3OH)2 (HOBz? benzoic acid) has been studied. We use isosceles triangle model and molecular field correction to fit the experimental magnetic susceptibility data. It shows that an intramolecular antiferromagnetic exchange interaction occurs with J = -31.27 cm?1, J'= -27.26 cm?1, and a weaker intermolecular antiferromagnetic exchange interaction occurs with zJ' = - 3.76 cm?1. We give the d5-d5-d5 energy level diagram of triiron(III) complex as a function of J'/J. From the diagram we can get the total spin ST of the complex as 1/2 in the ground state.  相似文献   

3.
Structure and Thermal Decomposition of Bis(triethanolamine)copper(II) Acetate [Cu{N(CH2CH2OH)3}2](CH3COO)2 Bis(triethanolamine)copper(II) acetate [Cu{N · (CH2CH2OH)3}2](CH3COO)2 was prepared using the basic components; the structure was determined by single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P21/c with a = 9.101 Å, b = 13.136 Å, c = 9.819 Å, β = 111.63°. Details of the synthesis, X-ray data, and the thermal decomposition are reported.  相似文献   

4.
测定了三核苯甲酸铁配合物[Fe3O(OBz)6(CH3OH)3](NO3)(CH3OH)2(OBz-=苯甲酸根)的电子光谱,应用配体场理论和T-S图求得配体场参数10Dq=12457cm-1.用CNDO/2方法对其简化模型进行了计算。  相似文献   

5.
The reaction of Cu(ClO4)2.6-H2O and n-propylamine in methanol gives two high-nuclearity products of well-defined compositions. At amine concentrations greater than seven equivalents compared to copper ion concentration, the system fixes carbon dioxide from air to form the one-dimensional carbamate-bridged coordination polymer, {[Cu(mu2-O,O'-O2CNH(CH2)2CH3)(NH2(CH2)2CH3)3](ClO4)}n ({1-ClO4}n). Lower relative amine concentrations lead to the self-assembly of an octanuclear copper-amine-hydroxide cluster [Cu8(OH)10(NH2(CH2)2CH3)12]6+ (2). Both compounds exhibit unique structures: {1-ClO4}n is the first mu2-O,O'-mono-N-alkylcarbamate-linked coordination polymer and 2 is the largest copper-hydroxide-monodentate amine cluster identified to date. The crystal structures indicate that the size of the n-propyl group is probably crucial for directing the formation of these compounds. Magnetic susceptibility studies indicate very weak antiferromagnetic coupling for 1. The octanuclear cluster 2 displays slightly stronger net antiferromagnetic coupling, despite the presence of a number of Cu-O(H)-Cu angles below the value of about 97 degrees that would normally be expected to yield ferromagnetic coupling.  相似文献   

6.
[Pb(TpyCl)Cl][Pb(TpyCl)Cl2][PbCl3](CH3OH) ( 1 ), a new coordination polymer of divalent lead with the ligand 4′‐chloro‐2,2′:6′,2"‐terpyridine (TpyCl), was obtained as single crystals by the branched tube method. The crystal structure contains three complexes, the cationic [Pb(TpyCl)Cl]+, the neutral [Pb(TpyCl)Cl2] and the anionic [PbCl3], which are connected through bridging chlorides and hydrogen bonds to a two‐dimensional coordination polymer. In all three complexes, the arrangement around the Pb2+ ion suggests the existence of a stereoactive lone pair.  相似文献   

7.
The reflected shock tube technique with multipass absorption spectrometric detection of OH radicals at 308 nm (corresponding to a total path length of approximately 4.9 m) has been used to study the dissociation of methanol between 1591 and 2865 K. Rate constants for two product channels [CH3OH + Kr --> CH3 + OH + Kr (1) and CH3OH + Kr --> 1CH2 + H2O + Kr (2)] were determined. During the course of the study, it was necessary to determine several other rate constants that contributed to the profile fits. These include OH + CH3OH --> products, OH + (CH3)2CO --> CH2COCH3 + H2O, and OH + CH3 --> 1,3CH2 + H2O. The derived expressions, in units of cm(3) molecule(-1) s(-1), are k(1) = 9.33 x 10(-9) exp(-30857 K/T) for 1591-2287 K, k(2) = 3.27 x 10(-10) exp(-25946 K/T) for 1734-2287 K, kOH+CH3OH = 2.96 x 10-16T1.4434 exp(-57 K/T) for 210-1710 K, k(OH+(CH3)(2)CO) = (7.3 +/- 0.7) x 10(-12) for 1178-1299 K and k(OH+CH3) = (1.3 +/- 0.2) x 10(-11) for 1000-1200 K. With these values along with other well-established rate constants, a mechanism was used to obtain profile fits that agreed with experiment to within <+/-10%. The values obtained for reactions 1 and 2 are compared with earlier determinations and also with new theoretical calculations that are presented in the preceding article in this issue. These new calculations are in good agreement with the present data for both (1) and (2) and also for OH + CH3 --> products.  相似文献   

8.
The thermal behaviours of certain salts of the complex “ethriol-” and “methriolboric” acids have been investigated by means of Derivatograph and IR spectra. It is shown that compounds of this type decompose in three main stages on heating: 1) the crystallization water is lost, 2) the condensation water is lost and dimers are formed containing bridge bonds B4-O-B4; 3) up to 600–700? all the organic matter is lost; the residue is the corresponding borate (1 ∶ 1). The possibility of performing a fast full analysis by means of the TG and DTG curves has been demonstrated.  相似文献   

9.
The crystal and molecular structure of [ (PPh3)2Cu(O2CPhOH)] @ CH3CH2OH has been determined by X-raycrystallography. It crystallizes in the monoclinic system, space group P21/c, with Mr = 771.26 (C45H41CuO4P2),a = 0. 96413(19) nm, b= 1. 5780(3) nm, c = 2. 5426(5) nm, β = 100. 27(3)°, V= 3. 8065(13) nm3, The titlecompound consists of discrete copper (Ⅰ) bis(triphenylphosphine) salicylate molecules and ethanol solvate. EachCu is coordinated to two phosphorus atoms of triphenylphosphine ligands and one of carboxylate oxygens in a trigonalplanar geometry. In the solid, the intramolecular hydrogen bond and extensive intermolecular interaction connecting(PPh3) 2Cu(O2CPhOH) molecules and ethanol solvate form hydrogen bonds network which stabilize the crystalstructure.  相似文献   

10.
The reaction kinetics of chlorine atoms with a series of partially fluorinated straight-chain alcohols, CF(3)CH(2)CH(2)OH (1), CF(3)CF(2)CH(2)OH (2), CHF(2)CF(2)CH(2)OH (3), and CF(3)CHFCF(2)CH(2)OH (4), were studied in the gas phase over the temperature range of 273-363 K by using very low-pressure reactor mass spectrometry. The absolute rate coefficients were given by the expressions (in cm(3) molecule(-1) s(-1)): k(1) = (4.42 +/- 0.48) x 10(-11) exp(-255 +/- 20/T); k(1)(303) = (1.90 +/- 0.17) x 10(-11), k(2) = (2.23 +/- 0.31) x 10(-11) exp(-1065 +/- 106/ T); k(2)(303) = (6.78 +/- 0.63) x 10(-13), k(3) = (8.51 +/- 0.62) x 10(-12) exp(-681 +/- 72/T); k(3)(303) = (9.00 +/- 0.82) x 10(-13) and k(4) = (6.18 +/- 0.84) x 10(-12) exp(-736 +/- 42/T); k(4)(303) = (5.36 +/- 0.51) x 10(-13). The quoted 2sigma uncertainties include the systematic errors. All title reactions proceed via a hydrogen atom metathesis mechanism leading to HCl. Moreover, the oxidation of the primarily produced radicals was investigated, and the end products were the corresponding aldehydes (R(F)-CHO; R(F) = -CH(2)CF(3), -CF(2)CF(3), -CF(2)CHF(2), and -CF(2)CHFCF(3)), providing a strong experimental indication that the primary reactions proceed mainly via the abstraction of a methylenic hydrogen adjacent to a hydroxyl group. Finally, the bond strengths and ionization potentials for the title compounds were determined by density functional theory calculations, which also suggest that the alpha-methylenic hydrogen is mainly under abstraction by Cl atoms. The correlation of room-temperature rate coefficients with ionization potentials for a set of 27 molecules, comprising fluorinated C2-C5 ethers and C2-C4 alcohols, is good with an average deviation of a factor of 2, and is given by the expression log(k) (in cm(3) molecule(-1) s(-1)) = (5.8 +/- 1.4) - (1.56 +/- 0.13) x (ionization potential (in eV)).  相似文献   

11.
The mechanisms and the kinetics of the OH radical reaction with 4-hydroxy-2-butanone (4H2B) are investigated theoretically. Five hydrogen-abstraction channels are identified for the title reaction. The first potential energy profile of the title reaction is presented. The rate constants for each reaction channel are evaluated using transition state theory method in the temperature range of 200–1,000 K. Branching ratio of the title reaction is calculated and plotted. It is shown that the “in-plane hydrogen abstraction” from the methoxy end is the dominant channel, and the other hydrogen-abstraction channels play the minor role. The comparison between theoretical and experimental results is discussed. The three-parameter Arrhenius expression for the rate constants is also provided.  相似文献   

12.
利用三苯基氯化锡和对苯二甲酸二钠、哌嗪荒酸二钠在甲醇中反应 ,合成了双核有机锡 (Ⅳ )配合物 [Ph3 Sn (CH3 OH)O2 CC6H4 CO2 (CH3 OH)SnPh3 ]·2CH3 OH (1)和 [Ph3 SnS2 CN(CH2 CH2 ) 2 NCS2 SnPh3 ]·2CH3 OH (2 ) .通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征 .用X射线单晶衍射测定了这两个化合物的晶体结构 .化合物 1为单斜晶系 ,空间群P2 1/n ,a =1.5 199(5 )nm ,b =0 .90 0 0 (3)nm ,c =1.82 0 6 (6 )nm ,β =113.970 (5 )° ,Z =2 ,V =2 .2 75 5(13)nm3 ,Dc=1.413g/cm3 ,μ =1.146mm-1,F(0 0 0 ) =980 ,R1=0 .0 35 3,wR2 =0 .0 6 0 6 .化合物 2为单斜晶系 ,空间群P2 1/c,a =1.5 0 6 6 (5 )nm ,b =1.0 875 (4 )nm ,c =1.35 42 (5 )nm ,β =91.6 14(5 )°,Z =2 ,V =2 .2 178(14)nm3 ,Dc=1.498g/cm3 ,μ =1.35 1mm-1,F(0 0 0 ) =10 0 8,R1=0 .0 40 1,wR2 =0 .1148.在 1和 2的晶体中 ,锡原子呈五配位畸变三角双锥构型 .配合物 1由未配位的甲醇分子通过氢键作用形成二维网状结构  相似文献   

13.
The mechanism of the gas-phase reaction OH with CH2=C(CH3)CH2OH (2-methyl-2-propen-1-ol) has been elucidated using high-level ab initio method, i.e., CCSD(T)/6-311++g(d,p)//MP2(full)/6-311++g(d,p). Various possible H-abstraction and addition–elimination pathways are identified. The calculations indicate that the addition–elimination mechanism dominates the OH+MPO221 reaction. The addition reactions between OH radicals and CH2=C(CH3)CH2OH begin with the barrierless formation of a pre-reactive complex in the entrance channel, and subsequently the CH2(OH)C(CH3)CH2OH (IM1) and the CH2C(OH)(CH3)CH2OH (IM2) are formed by OH radicals’ electrophilic additions to the double bond. IM1 can easily rearrange to IM2 via a 1,2-OH migration. Subsequently, rearrangement of IM2 to form (CH3)2C(OH)CH2O (IM11) followed by dissociation to HCHO + (CH3)2COH (P21) is the most favorable pathway. The decomposition of IM2 to CH2OH + CH2=C(OH)CH3 (P16) is the secondary pathway. The other pathways are not expected to play any important role in forming final products.  相似文献   

14.
The intrinsic methylating abilities of the known biological methylating zwitterionic agents, dimethylsulfonioacetate (DMSA), (CH(3))(2)S?CH(2)CO(2)(-) (1) and glycine betaine (GB), (CH(3))(3)N?CH(2)CO(2)(-) (2), have been examined via a range of gas phase experiments involving collision-induced dissociation (CID) of their proton-bound homo- and heterodimers, including those containing the amino acid arginine. The relative yields of the products of methyl cation transfer are consistent in all cases and show that protonated DMSA is a more potent methylating agent than protonated GB. Since methylation can occur at more than one site in arginine, the [M+CH(3)](+) ion of arginine, formed from the heterocluster [DMSA+Arg+H](+), was subject to an additional stage of CID. The resultant CID spectrum is virtually identical to that of an authentic sample of protonated arginine-O-methyl ester but is significantly different to that of an authentic sample of protonated N(G)-methyl arginine. This suggests that methylation has occurred within a salt bridge complex of [DMSA+Arg+H](+), in which the arginine exists in the zwitterionic form. Finally, density functional theory calculations on the model salts, (CH(3)CO(2)(-))[(CH(3))(3)S(+)] and (CH(3)CO(2)(-))[(CH(3))(4)N(+)], show that methylation of CH(3)CO(2)(-) by (CH(3))(3)S(+) is both kinetically and thermodynamically preferred over methylation by (CH(3))(4)N(+).  相似文献   

15.
用X-射线晶体结构衍射法测定了〔C5H4C(CH3)2CH2CH=CH2〕Sm(OH)Cl·2MgCl2·4THF的晶体结构。它属三斜晶系,空间群为P1,a=10.773(2),b=12.836(3),c=15.478(3),α=111.46(3),β=107.71(3),γ=92.54(3)°,V=1868(1)3,Mr=827.91,Dx=1.472g/cm3,μ=2.0006mm-1,F(000)=840,Z=2,R=0.041,wR=0.050(I≥3σ(I))。分子中Sm原子的配位数为8,形成一个严重扭曲的八面体结构;2个Mg原子的配位情况相似,它们的配位数都是6,分别构成2个扭曲的八面体。这3个八面体通过3个共平面联接  相似文献   

16.
The silver-dppm complex, [Ag2(dppm)2(NMP)2](SbF6)2·4H2O·3CH2Cl2 1 (NMP = 2- (4-dimethylaminophenyl)imidazo(4,5-f)(1,10)phenanthroline, dppm = diphenylphosphinomethane), was synthesized and its structure was determined by X-ray diffraction. The crystal belongs to mono- clinic, space group C2/c, Mr = 2461.61, a = 21.57(10), b = 22.48(6), c = 22.53(6) (A), β = 101.29(2)o, V = 10713(64) (A)3, Z = 4, Dc = 1.526 g/cm3, μ = 1.141 mm-1, F(000) = 4920, R = 0.0664 and Wr = 0.1774 for 8524 observed reflections (I > 2σ(I)). Complex 1 exists as a centrosymmetric dimmer. The two dppm molecules bridge two AgNMP moieties to form an eight-membered Ag2P4C2 metal- lacyclic ring with ligand NMP chelating to each Ag. It appears photoluminescence λ(max = 625 nm) at room temperature and makes red shift compared with free ligand NMP λ(max = 522 nm). DFT calculation indicates that the emission of 1 originates from singlet metal-perturbed ILCT excited state.  相似文献   

17.
A kinetic study of [OsO(4)] reduction by aliphatic alcohols (MeOH and EtOH) was performed in a 2.0 M NaOH matrix at 298.1 K. The rate model that best fitted the UV-VIS data supports a one-step, two electron reduction of Os(VIII) (present as both the [Os(VIII)O(4)(OH)](-) and cis-[Os(VIII)O(4)(OH)(2)](2-) species in a ratio of 0.34:0.66) to form the trans-[Os(VI)O(2)(OH)(4)](2-) species. The formed trans-[Os(VI)O(2)(OH)(4)](2-) species subsequently reacts relatively rapidly with the cis-[Os(VIII)O(4)(OH)(2)](2-) complex anion to form a postulated [Os(VII)O(3)(OH)(3)](2-) species according to: cis-[Os(VIII)O(4)(OH)(2)](2-) + trans-[Os(VI)O(2)(OH)(4)](2-) (k+2) (k-2) 2[Os(VII)O(3)(OH)(3)](2-). The calculated forward, k(+2), and reverse, k(-2), reaction rate constants of this comproportionation reaction are 620.9 ± 14.6 M(-1) s(-1) and 65.7 ± 1.2 M(-1) s(-1) respectively. Interestingly, it was found that the postulated [Os(VII)O(3)(OH)(3)](2-) complex anion does not oxidize MeOH or EtOH. Furthermore, the reduction of Os(VIII) with MeOH or EtOH is first order with respect to the aliphatic alcohol concentration. In order to corroborate the formation of the [Os(VII)O(3)(OH)(3)](2-) species predicted with the rate model simulations, several Os(VIII)/Os(VI) mole fraction and mole ratio titrations were conducted in a 2.0 M NaOH matrix at 298.1 K under equilibrium conditions. These titrations confirmed that the cis-[Os(VIII)O(4)(OH)(2)](2-) and trans-[Os(VI)O(2)(OH)(4)](2-) species react in a 1:1 ratio with a calculated equilibrium constant, K(COM), of 9.3 ± 0.4. The ratio of rate constants k(+2) and k(-2) agrees quantitatively with K(COM), satisfying the principle of detailed balance. In addition, for the first time, the molar extinction coefficient spectrum of the postulated [Os(VII)O(3)(OH)(3)](2-) complex anion is reported.  相似文献   

18.
The coordination of Cd(2+) with P(CH(2)OH)(3) (THP) in methanol was followed by (31)P and (111)Cd NMR techniques. A cadmium-to-phosphine coordination ratio of 1:3 has been established, and effective kinetic parameters have been calculated. Air oxidation of THP in the presence of CdCl(2) at room temperature produces coordination polymer (3)(∞)[Cd(3)Cl(6)(OP(CH(2)OH)(3))(2)] (1). The same oxidation reaction at 70 °C gives another coordination polymer, (∞)[CdCl(2)(OP(CH(2)OH)(3))] (2). Complexes 1 and 2 are the first structurally characterized complexes featuring OP(CH(2)OH)(3) as a ligand that acts as a linker between Cd atoms. The addition of NaBPh(4) to the reaction mixture gives coordination polymer (∞)[Na(2)CdCl(2)(O(2)P(CH(2)OH)(2))(2)(H(2)O)(3)] (3) with (HOCH(2))(2)PO(2)(-) as the ligand. Coordination polymers 1-3 have been characterized by X-ray analysis, elemental analysis, and IR spectroscopy.  相似文献   

19.
The reaction of triplet methylene with methanol is a key process in alcohol combustion but surprisingly this reaction has never been studied. The reaction mechanism is investigated by using various high-level ab initio methods, including the complete basis set extrapolation (CBS-QB3 and CBS-APNO), the latest Gaussian-n composite method (G4), and the Weizmann-1 method (W1U). A total of five product channels and six transition states are found. The dominant mechanism is direct hydrogen abstraction, and the major product channel is CH(3) + CH(3)O, involving a weak prereactive complex and a 7.4 kcal/mol barrier. The other hydrogen abstraction channel, CH(3) + CH(2)OH, is less important even though it is more exothermic and involves a similar barrier height. The rate coefficients are predicted in the temperature range 200-3000 K. The tunneling effect and the hindered internal rotational freedoms play a key role in the reaction. Moreover, the reaction shows significant kinetic isotope effect.  相似文献   

20.
The structural characterization of two new sodium phenolate complexes, containing ortho-amino substituents, enables the influence of intramolecular coordination on the aggregation of sodium phenolate complexes to be determined. Crystals of hexameric [NaOC(6)H(4)(CH(2)NMe(2))-2](6) (1a) are monoclinic, space group P2(1)/c, with a = 11.668(4) ?, b = 18.146(4) ?, c = 14.221(5) ?, beta = 110.76(3) ?, V = 2815.5(16) ?(3), and Z = 2; R = 0.0736 for 2051 reflections with I > 2.0sigma(I). Complex 1a contains a unique Na(6)O(6) core, consisting of two face-fused cubes, with the ortho-amino substituent of each phenolate coordinating to a sodium atom. In addition, two of the phenolate ligands have an eta(2)-arene interaction with an additional sodium atom in the core. Crystals of dimeric [(NaOC(6)H(2)(CH(2)NMe(2))(2)-2,6-Me-4)(HOC(6)H(2)(CH(2)NMe(2))(2)-2,6-Me-4)](2) (2b) are triclinic, space group P&onemacr;, with a = 10.0670(8) ?, b = 10.7121(7) ?, c = 27.131(3) ?, alpha = 92.176(8) degrees, beta = 99.928(8) degrees, gamma = 106.465(6) degrees, V = 2752.1(4) ?(3), and Z = 2; R = 0.0766 for 5329 reflections with I > 2.0sigma(I). Dimeric complex 2b contains two phenolate ligands, which bridge the two sodium atoms, each coordinating with one ortho-amino substituent to a sodium atom, while the second available ortho-amino substituent remains pendant. The coordination sphere of each sodium atom is completed by a (neutral) bidentate O,N-coordinated parent phenol molecule. The second ortho-amino substituent of this neutral phenol is involved in a hydrogen bridge with its acidic hydrogen. On the basis of these two new crystal structures and previously reported solid state structures for sodium phenolate complexes, it is shown that the introduction of first one and then two ortho-amino substituents into the phenolate ligands successively lowers the degree of association of these complexes in the solid state. In this process, the basic Na(2)O(2) building block of the molecular structures remains intact.  相似文献   

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