一个吡啶二甲酸镉配位聚合物的合成、晶体结构及荧光性质

通过水热方法,采用H3CAM(H3CAM=4-hydroxy-pyridine-2,6-dicarboxylic acid)与Cd(NO3)2.4H2O反应,合成了1个镉配位聚合物[Cd4(HCAM)4(H2O)8]n(1),并对其结构和荧光性质进行了研究。结构分析结果表明该配合物属于单斜晶系,C2/c空间群。四个HCAM2-配体桥联4个镉离子形成了1个四核镉单元。这些孤立的单元通过氢键作用形成了1个三维配位框架。研究表明,该配合物在室温下能发出兰色荧光。     

Determining the main thermodynamic parameters of caffeine melting by means of DSC

The temperature and enthalpy of the melting of caffeine, which are 235.5 ± 0.1°C and 19.6 ± 0.2 kJ/mol, respectively, are determined by DSC. The melting entropy and the cryoscopic constant of caffeine are calculated.     

Extraction of lanthanides(III) by phosphorylated naphthyridine ligands from carbonate solutions

The extraction capacities and selectivities of 1,8-naphthyridine-based neutral organophosphorus reagents in extracting trivalent lanthanides (Ln, Nd, Ho, Yb) from carbonate solutions were studied. The length and nature of the linker between the naphthyridine and phosphoryl moieties were found to have considerable influence on the efficiency and selectivity of lanthanide extraction.     

Gibbs energy increment and minimum work of separation during the distillation of a dilute solution in a multistep cascade

The Gibbs energy increment during the distillation of a dilute solution in a separation cascade was calculated. An interpretation of the minimum work thermodynamically required during the symmetric separation of a binary mixture is suggested.     

Efficiency of electrochemical amination of anisole in aqueous-organic solutions of 4 M H2SO4

Cathodically initiated amination of anisole has been performed with the Ti(IV)-NH₂OH system in aqueous solutions of 4 M H₂SO₄ containing high concentration of acetic acid or acetonitrile. In electrolyses performed to reach full conversion of hydroxylamine, the isomeric anisidines obtained (2 para/ortho ∼ 3.9) with total yields referred to the current and amino radical source exceeded 80%.     

Synthesis and Properties of Novel Luminescent Compounds Containing Triphenylamine and Bipyridine Units

Blue luminescent compounds T1-T4 containing triphenylamine donors,bipyridine acceptors and olefinic linkers were synthesized and characterized by 1H NMR,13C NMR and high resolution mass spectrometry(HR...     

Prediction of the enthalpy of vaporization based on modified Randi? indices. Ethers

A method to predict the enthalpies of vaporization of ethers with various structures under normal conditions using a modified Randič method is proposed.     

Re-determination of the crystal structure of heyrovskyite mineral Pb6Bi2S9 (Kudryavyi Volcano, Iturup Island, Kurils, Russia)

Heyrovskyite mineral Pb₆Bi₂S₉ from fumarole exhalations of the Kudryavyi volcano (Iturup island, Kurils, Russia) is studied by X-ray crystallography (Bruker Nonius X8 Apex with a 4K CCD detector, R = 0.0405). Unit cell parameters are: a = 4.1457(1) ?, b = 13.7421(5) ?, c = 31.5005(12) ?, V = 1794.6(1) ?³, Z = 4, d _x = 7.216 g/cm³, Cmcm space group, R=0.0405. The resulted structure is similar to the known structures of heyrovskyites from other deposits with some variation in the cation composition.     

Influence of hydrogen bonds on the molecular structure and conformations of two (C30H48O2) pentacyclic triterpene isomers

The structural study of two (C₃₀H₄₈O₂) pentacyclic triterpene (PCTT) isomers is presented. These terpenes, known as 30-hydroxy-lup-20(29)-en-3-one (1) and (11α)-11-hydroxy-lup-20(29)-en-3-one (2), were isolated from Maytenus imbricata Mart. Ex Reissek (Celastraceae). The molecular structure of 1 and 2 differs in the position of the hydroxyl group. Both compounds crystallize in non-centrosymmetric space groups with two molecules in the asymmetric unit. The crystal structure of 1 shows a triclinic P1 space group (a = 9.5518(1) ?, b = 9.7083(1) ?, c = 14.4696(2) ?, α = 93.832(1)°, β = 102.833(1)°, and γ = 103.307(1)°), while compound 2 crystallizes in a monoclinic P2₁ one (a = 13.4439(16) ?, b = 14.4463(14) ?, c = 13.5224(9) ? and β = 99.703(8)°). The two molecules independent by symmetry of 1 differ slightly due to the presence of static disorder in oxygen atoms. In addition, the intermolecular geometries of 1 and 2 were analysed, and in each isomer the crystal packing is stabilized by O-H…O intermolecular hydrogen bonds and van der Waals forces.