Synthesis and spectroscopy of N3P3X5OCH=CH2 (X = Cl, F, OCH3, OCH2CF3, N(CH3)2) and N3P3X4(OCH=CH2)2 (X = Cl, N(CH3)2). Correlations of ultraviolet photoelectron spectroscopy and nuclear magnetic resonance data to electronic and geometrical structure

The syntheses of the vinyloxycyclotriphosphazene derivatives N3P3X5OCH=CH2 (X = OMe, OCH2CF3) and the N3P3(NMe2)4(OCH=CH2)2 isomeric mixture along with improved preparations of N3P3X5OCH=CH2 (X = F, NMe2) are reported. The interactions between the vinyloxy function and the cyclophosphazene in these and the previously reported N3P3Cl5 (OCH=CH2) and N3P3F6-n(OCH=CH2)n (n = 1-4) have been examined by ultraviolet photoelectron spectroscopy (UPS) and NMR spectroscopy. The UPS data for the chloro and fluoro derivatives show a strong electron-withdrawing effect of the phosphazene on the olefin that is mediated with decreasing halogen substitution. The 1H and 13C NMR data for N3P3X5OCH=CH2 (X = F, Cl, OMe, OCH2CF3, NMe2) show significant changes as a function of the phosphazene substituent. There is a linear correlation between the beta-carbon chemical shift on the vinyloxy unit and the phosphorus chemical shift at the vinyloxyphosphorus centers. The chemical shifts of the different phosphorus centers on each ring are also related in a linear fashion. These relationships may be understood in terms of the relative electron donor-acceptor abilities of the substituents on the phosphazene ring. The 1H NMR spectra of the N3P3(NMe2)4(OCH-CH2)2 isomeric mixture allow for assignment of the relative amounts of cis and trans isomers. A model for the observed cis preference in the formation of N3P3Cl4(OCH=CH)2 is presented.     

Energetics of the O-H bond and of intramolecular hydrogen bonding in HOC6H4C(O)Y (Y = H, CH3, CH2CH=CH2, C[triple bond]CH, CH2F, NH2, NHCH3, NO2, OH, OCH3, OCN, CN, F, Cl, SH, and SCH3) compounds

The energetics of the phenolic O-H bond in a series of 2- and 4-HOC 6H 4C(O)Y (Y = H, CH3, CH 2CH=CH2, C[triple bond]CH, CH2F, NH2, NHCH 3, NO2, OH, OCH3, OCN, CN, F, Cl, SH, and SCH3) compounds and of the intramolecular O...H hydrogen bond in 2-HOC 6H 4C(O)Y, was investigated by using a combination of experimental and theoretical methods. The standard molar enthalpies of formation of 2-hydroxybenzaldehyde (2HBA), 4-hydroxybenzaldehyde (4HBA), 2'-hydroxyacetophenone (2HAP), 2-hydroxybenzamide (2HBM), and 4-hydroxybenzamide (4HBM), at 298.15 K, were determined by micro- or macrocombustion calorimetry. The corresponding enthalpies of vaporization or sublimation were also measured by Calvet drop-calorimetry and Knudsen effusion measurements. The combination of the obtained experimental data led to Delta f H m (o)(2HBA, g) = -238.3 +/- 2.5 kJ.mol (-1), DeltafHm(o)(4HBA, g) = -220.3 +/- 2.0 kJ.mol(-1), Delta f H m (o)(2HAP, g) = -291.8 +/- 2.1 kJ.mol(-1), DeltafHm(o)(2HBM, g) = -304.8 +/- 1.5 kJ.mol (-1), and DeltafHm(o) (4HBM, g) = -278.4 +/- 2.4 kJ.mol (-1). These values, were used to assess the predictions of the B3LYP/6-31G(d,p), B3LYP/6-311+G(d,p), B3LYP/aug-cc-pVDZ, B3P86/6-31G(d,p), B3P86/6-311+G(d,p), B3P86/aug-cc-pVDZ, and CBS-QB3 methods, for the enthalpies of a series of isodesmic gas phase reactions. In general, the CBS-QB3 method was able to reproduce the experimental enthalpies of reaction within their uncertainties. The B3LYP/6-311+G(d,p) method, with a slightly poorer accuracy than the CBS-QB3 approach, achieved the best performance of the tested DFT models. It was further used to analyze the trends of the intramolecular O...H hydrogen bond in 2-HOC 6H 4C(O)Y evaluated by the ortho-para method and to compare the energetics of the phenolic O-H bond in 2- and 4-HOC 6H 4C(O)Y compounds. It was concluded that the O-H bond "strength" is systematically larger for 2-hydroxybenzoyl than for the corresponding 4-hydroxybenzoyl isomers mainly due to the presence of the intramolecular O...H hydrogen bond in the 2-isomers. The observed differences are, however, significantly dependent on the nature of the substituent Y, in particular, when an intramolecular H-bond can be present in the radical obtained upon cleavage of the O-H bond.     

Synthesis and photoelectron spectroscopic studies of N(CH2CH2NMe)3P=E (E = O, S, NH, CH2)

The synthesis and the crystal and molecular structure of N(CH(2)CH(2)NMe)(3)P=CH(2) is reported. The P-N(ax) distance is rather long in N(CH(2)CH(2)NMe)(3)P=CH(2). The ylide N(CH(2)CH(2)NMe)(3)P=CH(2) proved to be a stronger proton acceptor than proazaphosphatrane N(CH(2)CH(2)NMe)(3)P, since it was shown to deprotonate N(CH(2)CH(2)NMe)(3)PH(+). The extremely strong basicity of the ylide is in accordance with its low ionization energy (6.3 eV), which is the lowest in the presently investigated series N(CH(2)CH(2)NMe)(3)P=E (E: CH(2), NH, lone pair, O and S), and to the best of our knowledge it is the smallest value observed for a non-conjugated phosphorus ylide. Computations reveal the existence of two bond strech isomers, and the stabilization of the phosphorus centered cation by electron donation from the equatorial and the axial nitrogens. Similar stabilizing effects operate in the case of protonation of E. A fine balance of these different interactions determines the P-N(ax) distance, which is thus very sensitive to the level of the theory applied. According to the quantum mechanical calculations, methyl substitution at the equatorial nitrogens flattens the pyramidality of this atom, increasing its electron donor capability. As a consequence, the PN(ax) distance in the short-transannular bonded protonated systems and the radical cations is longer by about 0.5 A in the N(eq)(Me) than in the N(eq)(H) systems. Accordingly, isodesmic reaction energies show that a stabilization of about 25 and 10 kcal/mol is attributable to the formation of the transannular bond in case of N(eq)(H) and the experimentally realizable N(eq)(Me) species, respectively.     

A theoretical approach to the thermochemistry of the polymerization of some derivatives of the monomers CH2X (X = CH2, NH,O)

In this work, we have calculated the thermodynamic parameters of the polymerization of some derivatives of the species CH₂X (X = CH₂, NH, O), using ab initio methods of quantum chemistry and the usual formalism of statistical thermodynamics. It is shown that the Gibbs functions ΔG(l, c) corresponding to CH₂NOCH₃, CNCHNCN, CF₂O and all the percyano derivatives are largely positive which indicates that the spontaneous (radical or ionic) chain polymerization of these monomers is thermodynamically prohibited.     

Two new XP(O)[NHC(CH3)3]2 phosphoramidates,with X = (CH3)2N and [(CH3)3CNH]2P(O)(O)

In N,N′‐di‐tert‐butyl‐N′′,N′′‐dimethylphosphoric triamide, C₁₀H₂₆N₃OP, (I), and N,N′,N′′,N′′′‐tetra‐tert‐butoxybis(phosphonic diamide), C₁₆H₄₀N₄O₃P₂, (II), the extended structures are mediated by P(O)...(H—N)₂ interactions. The asymmetric unit of (I) consists of six independent molecules which aggregate through P(O)...(H—N)₂ hydrogen bonds, giving R₂¹(6) loops and forming two independent chains parallel to the a axis. Of the 12 independent tert‐butyl groups, five are disordered over two different positions with occupancies ranging from to . In the structure of (II), the asymmetric unit contains one molecule. P(O)...(H—N)₂ hydrogen bonds give S(6) and R₂²(8) rings, and the molecules form extended chains parallel to the c axis. The structures of (I) and (II), along with similar structures having (N)P(O)(NH)₂ and (NH)₂P(O)(O)P(O)(NH)₂ skeletons extracted from the Cambridge Structural Database, are used to compare hydrogen‐bond patterns in these families of phosphoramidates. The strengths of P(O)[...H—N]_x (x = 1, 2 or 3) hydrogen bonds are also analysed, using these compounds and previously reported structures with (N)₂P(O)(NH) and P(O)(NH)₃ fragments.     

Influence of Organic-Cation Defects on Optoelectronic Properties of ASnI3 Perovskites A=HC(NH2)2, CH3NH3

Tin organic–inorganic halide perovskites (tin OIHPs) possess a desirable band gap and their power conversion efficiency (PCE) has reached 14 %. A commonly held view is that the organic cations in tin OIHPs would have little impact on the optoelectronic properties. Herein, we show that the defective organic cations with randomly dynamic characteristics can have marked effect on optoelectronic properties of the tin OIHPs. Hydrogen vacancies originated from the proton dissociation from FA [HC(NH₂)₂] in FASnI₃ can induce deep transition levels in the band gap but yield relatively small nonradiative recombination coefficients of 10⁻¹⁵ cm³ s⁻¹, whereas those from MA (CH₃NH₃) in MASnI₃ can yield much larger nonradiative recombination coefficients of 10⁻¹¹ cm³ s⁻¹. Additional insight into the “defect tolerance” is gained by disentangling the correlations between dynamic rotation of organic cations and charge-carrier dynamics.     

(NH2CH2CH2NH3)4[WⅤO2(OC6H4O)2]2(NH3CH2CH2NH3)·H2O的合成、晶体结构、EPR以及与同构物的比较

Cis-dioxo-catecholatotungsten(Ⅴ) complex (NH₂CH₂CH₂NH₃)₄[W^ⅤO₂(OC₆H₄O)₂]₂(NH₃CH₂CH₂NH₃)·H₂O (1) was synthesized at room temperature by the reaction of tetrabutyl ammonium decatungstate with catechol in the mixed solvent of CH₃OH, CH₃CN and NH₂CH₂CH₂NH₂. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P2₁/c,a=0.712 8(3) nm, b=3.082 3(11) nm, c=0.982 8(4) nm, β=102.639(6)°, V=2.106 8(14) nm³, Z=2, R₁=0.062 8, wR₂=0.183 7. Compared the complex with its analogous complexes (NH₂CH₂CH₂NH₃)₃[Mo^ⅤO₂(OC₆H₄O)₂], it is found that the coordination structure of W have no changes in the processing of electron transfer of tungsten-containing enzymes from the result of the similarity of the EPR spectra of the complexes and flavoenzyme from milk. CCDC: 272937.     

Reaction mechanism of HSH and CH3SH with NH2CH2COCH2X (X = F and Cl) molecules

The reaction mechanism of model compounds H₂S and CH₃SH for cysteine proteases with NH₂CH₂COCH₂X (X = F and Cl) molecules has been investigated using DFT methods with B3LYP and B3PW91 hybrid density functionals at 6‐31+G* basis sets. The single point energy has been calculated for the above reactions with B3LYP and B3PW91 functionals using aug‐cc‐PVDZ infinite basis set in both gas and solution phases. The intrinsic reaction coordinates calculations have been performed to confirm that each transition state is linked by the desired reactants and products. The geometries and relative energies for various stationary points have been determined and discussed. The zero point vibrational energy corrections have been made to predict the reliable energy. The negative value of reaction energy indicates that the overall reaction profile is found to be exothermic. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

Synthesis and structure of three clusters (μ-H)Os3 [μ-1,1,4-η2-XCH2CH(CO2CH2CH3)NH2](CO)9 (X = S,O)

Institute of Inorganic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 6, pp. 108–116, November–December, 1990.     

[(NH2CH2CH2NH3)2WⅥO2(NHC6H4NH)2]2(NH2CH2CH2NH2)·H2O配合物的合成与晶体结构

Cis-dioxo-tungsten(Ⅵ) complex, (NH₂CH₂CH₂NH₂)[(NH₂CH₂CH₂NH₃)₂W^ⅥO₂(NHC₆H₄NH)₂]₂·H₂O is synthesized at room temperature by the reaction of sodium tungstate with o-phenylenediamine. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P2₁/ c, a=0.712 8(2) nm, b=3.081 1(10) nm, c=0.981 9(3) nm, β=102.615(4)°, V=2.104 4(11) nm³, Z=2, μ=55.26 cm^-1, F(000)=1 176. Compared the complex with its analogous biomimetic complexes of the cofactor of molybdoenzymes and tungstoenzymses, it is found that the variance of the coordination atoms and the metal ions center have no influence on the coordination feature, and exhibits distored octahedral coordination with cis-dioxo o-phenylenediamine. CCDC: 252834.     

3-Dimethylarsino-propylamin, (CH3)2As?(CH2)3?NH2, und Bis-[3-amino-propyl]-methylarsan,CH3As[(CH2)3?NH2]2

3-Dimethylarsino-propylamine, (CH₃)₂As? (CH₂)₃? NH₂, and Bis-[3-aminopropyl]-methylarsane, CH₃As[(CH₂)₃? NH₂]₂ The reduction of the nitriles Me₂As(CH₂)₂? CN (Me?CH₃) and MeAs(CH₂CH₂? CN)₂ results in the formation of the arsines Me₂As(CH₂)₃? NH₂ and MeAs[(CH₂)₃? NH₂]₂, respectively. The reactivity of these compounds, especially the formation of carbonyl complexes and heterocyclic compounds are described.     

Changing Rules of Bonding Electron Pair Correlation Energies of CH3X （X = F, OH, NH2） Systems

1 INTRODUCTION It has been known that the electron correlation energy of molecular systems was, and still is, one of the most serious bottleneck problems to the chemis- try accuracy of computational quantum chemistry. Since L鰓din[1] gave the definition …     

CH2X(X=H,F,Cl)与臭氧反应机理的量子化学研究

用量子化学UMP2方法,在6-311++G**基组水平上研究了CH2X(X=H,F,Cl)与臭氧反应机理,全参数优化了反应过程中反应物、中间体、过渡态和产物的几何构型,在UQCISD(T)/6-311++G**水平上计算了它们的能量,并对它们进行了振动分析,以确定中间体和过渡态的真实性.从CH2X(X=H,F,Cl)与O3的反应机理的研究结果看,它们与O3反应的活性都比较强,相对而言,活性大小顺序为CH2F＞CH3＞CH2Cl,也就是说,CH2F自由基与臭氧间的反应活性最强,对大气臭氧的损耗将是最大的.同时研究还发现CH2X(X=H,F,Cl)系列自由基与O3的反应都是强放热反应.     

35Cl,79Br,81Br,and127I NQR spectra of HgHal2·XCH2CH2X complexes,X = OCH3, SCH3, and N(CH3)2

Conclusions From the NQR spectra of the halides HgHal₂ -D (Hal = Cl, Br, or I; D = SCH₃CH₂CH₂SCH₃, N(CH₃)₂ CH₂CH₂N(CH₃)₂, or OCH₃CH₂CH₂OCH₃) it follows that in their complexing ability the sulfur, nitrogen, and oxygen atoms can be arranged in the order: S > N > I. A structure with equivalent halogens is realized in the considered complexes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1895–1897, August, 1973.The authors consider it their duty to thank G. K. Semin for his valuable advice and interest in the work.     

Investigation of conformational state of molecules of dimephosphone H3C-(C=O)CH2-C(CH3)2-(P=O)(OCH3)2 by means of vibrational (IR,Raman) spectroscopy and molecular mechanics

On the basis of data obtained by vibrational spectroscopy and molecular mechanics, the molecules of dimephosphone are found to be conformationally inhomogeneous, representing a mixture of at least four spectrally distinguishable conformers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1577–1584, July, 1990.