Enantiomeric two-fold interpenetrated 3D zinc(ii) coordination networks as a catalytic platform: significant difference between water within the cage and trace water in transesterification

Abstract

Self-assembly of Zn(ClO) with 1,1,2,2-tetramethyl-1,2-di(pyridin-3-yl)disilane (L) as a bidentate N-donor gives rise to 3D coordination networks, [Zn(μ-OH)(L)](ClO)·5HO (1·5HO), of unique, 10-a srs net topology. An important feature is that two enantiomeric 3D frameworks, 4- and 4-[Zn(μ-OH)(L)](ClO)·5HO, are interpenetrated to form a racemic two-fold 3D network with cages occupied by two water molecules. Another structural characteristic is a C-symmetric planar Zn(μ-OH) 6-membered ring with tetrahedral Zn(ii) ions. The steric hindrance of substrates and trace water effects on transesterification catalysis using the network have been scrutinized. The coordination network acts as a remarkable heterogeneous transesterification catalytic system that shows both the significant steric effects of substrate alcohols and momentous water effects. The substrate activity is in the order ethanol > n-propanol > n-butanol > iso-propanol > 2-butanol > tert-butanol. For the reaction system, solvate water molecules within the cages of the interpenetrated 3D frameworks do not decrease the transesterification activity, whereas the trace water molecules in the substrate alcohols act as obvious obstacles to the reaction.

Emerging catalysis in biomass valorisation: simple Zn(II) catalysts for fatty acids esterification and transesterification

“…Notable results were obtained in the heterogeneous catalytic conversion of phenyl acetate in the corresponding butyl ester (entry 15.2). Finally, Ok‐Sang Jung et al [44] . combined Zn(ClO 4 ) 2 and 1,1,2,2‐tetramethyl‐1,2‐di(pyridin‐3‐yl)disilane to produce a 3D‐structure exhibiting heterogeneous catalytic activity.…”

“…In 2008 Cordeiro et al [21] efficiently used the layered hydroxide salt (LHS) [Zn 5 (OH) 8 (NO 3 ) 2 • 2H 2 O] as heterogeneous [44] catalysts for the esterification of lauric acid (and the transesterification of vegetable oils) with methanol and ethanol (entries 12.1-14.1). Based on PXRD and FTIR analyses of the recovered catalyst after the first run, they assumed replacement of the nitrate ion with laurate inside the crystalline lattice.…”

“…Notable results were obtained in the heterogeneous catalytic conversion of phenyl acetate in the corresponding butyl ester (entry 15.2). Finally, Ok-Sang Jung et al [44] combined Zn(ClO 4 ) 2 and 1,1,2,2-tetramethyl-1,2-di(pyridin-3-yl)disilane to produce a 3D-structure exhibiting heterogeneous catalytic activity. The yield was affected by the steric hindrance of the alcohol: ethanol gave the best results (entry 16.2), and the performance drastically decreased switching to propanol and butanol, but also in dependence of the amount of water in ethanol.…”

Cost-Effective Detection of Perfluoroalkyl Carboxylic Acids with Gas Chromatography: Optimization of Derivatization Approaches and Method Validation

“…Iso-propanol could achieve the esterification of most PFCAs, with PFBA as an exception. Nevertheless, the responses of the peaks by iso-propanol were much lower compared with those generated by methanol and ethanol, probably due to the relatively lower esterification efficiency caused by the steric hindrance in the molecular structure of iso-propanol [29,30]. Therefore, it can be concluded that the PFCAs esters approach was only feasible for the derivatization of PFCAs with a longer carbon chain (>C6), but inadequate for short-chained PFCAs, such as PFBA and PFPeA.…”

Structural properties of [Cu(ii)3L6] cages: bridged polyatomic anion effects on unprecedented efficiency of heterogeneous catechol oxidation

“…Current trends in research on desirable metal-organic coordination species have prioritized efficient applications. [1][2][3][4][5][6][7][8][9][10][11][12] Among the various relevant factors therein, counteranions play significant roles in both the process of topology formation and the functions of various coordination systems such as catenanes, rotaxanes, macrocycles, cages, and infinite networks. [13][14][15] In particular, a momentous challenge for comprehensive molecular cage systems that include anions is to discover task-specific functions such as recognition, adsorption/desorption, molecular containers, ion exchangers, chemo-sensors, proton conductivity, drug delivery, and catalysis.…”