Thermodynamic aspects of the host–guest chemistry of pyrogallol[4]arenes and peralkylated ammonium cations
作者:Bjoern Schnatwinkel、Mikhail V. Rekharsky、Ralf Brodbeck、Victor V. Borovkov、Yoshihisa Inoue、Jochen Mattay
DOI:10.1016/j.tet.2009.01.066
日期:2009.3
standard free energy (ΔGo), enthalpy (ΔHo), and entropy changes (ΔSo) for the complexation of pyrogallol[4]arenes with ammonium cations of different size and shape have been determined in ethanol at 298 K by isothermal titration calorimetry. The trends observed in the thermodynamic parameters for 1:1 and/or 1:2 host–guestcomplexation correspond to the systematic structural changes of the guest molecules
CRYSTAL STRUCTURES OF POLYNUCLEAR ANTIMONY BROMIDECOMPLEXES (Et(n-Pr)3N)3[Sb3Br12] AND (2,2′-bipyH)4[Sb4Br20]
作者:M. D. Petrov、M. N. Sokolov、V. P. Fedin、S. A. Adonin
DOI:10.1134/s0022476620110128
日期:2020.11
Trinuclear (Et(n-Pr)3N)3[Sb3Br12] (1) and tetranuclear (2,2′-bipyH)4[Sb4Br20] (2) bromoantimonates(III) are obtained by the reaction of solutions of bromides of the respective organic cations and Sb2O3 in HBr. The structures of 1 and 2 are studied by single crystal XRD. The [Sb3Br12]3– (1) anions belong to a previously unknown structure type of halide Sb(III) complexes.
Lanthanum silicate materials, their production and use
申请人:Council of Scientific and
Industrial Research
公开号:EP0225407A1
公开(公告)日:1987-06-16
Lanthanum silicate catalyst composites having, in terms of oxide mole ratios, the composition:
0 - 0.3 M₂O : La₂O₃ : 30-200 SiO₂
in which M is a monovalent cation. Such catalyst composites are made by reacting a lanthanum compound, an alkali metal compound and a silicon compound with a tetraalkyl ammonium salt of the formula:
R¹xR²yN⁺Z
in which R¹ and R² are C₂-C₄ alkyl groups, x and y are integers from 1 to 3 such that x + y is 4, and Z is a bromide or hydroxide ion, in an aqueous sulphuric acid medium to form a gel, heating the gel at a temperature of 100°C to 200°C, and filtering, drying and calcining the resulting solid material.
These materials are effective catalysts for the conversion of lower alcohols to lower olefins.
硅酸镧催化剂复合材料,其氧化物摩尔比组成如下
0 - 0.3 M₂O : La₂O₃ : 30-200 SiO₂
其中 M 为一价阳离子。这种催化剂复合材料是通过将镧化合物、碱金属化合物和硅化合物与式中的四烷基铵盐反应制成的:
R¹xR²yN⁺Z
其中 R¹ 和 R² 为 C₂-C₄烷基,x 和 y 为 1 至 3 的整数,使得 x + y 为 4,Z 为溴离子或氢氧根离子,在含水硫酸介质中形成凝胶,在 100°C 至 200°C 的温度下加热凝胶,并过滤、干燥和煅烧所得固体材料。
这些材料是低级醇转化为低级烯烃的有效催化剂。
Preferential orientations of structure directing agents in zeolites
作者:Eddy Dib、Antoine Gimenez、Tzonka Mineva、Bruno Alonso
DOI:10.1039/c5dt02558c
日期:——
The local structure of MFI-type zeolites is modified using asymmetric tetraalkylammonium structure directing agents R(Pr)3N+ cations that adopt preferential orientations at the crossing between channels.