2893-33-6Relevant articles and documents
Multiplying the electron storage capacity of a bis-tetrazine pincer ligand
Benson, Christopher R.,Hui, Alice K.,Parimal, Kumar,Cook, Brian J.,Chen, Chun-Hsing,Lord, Richard L.,Flood, Amar H.,Caulton, Kenneth G.
, p. 6513 - 6524 (2014)
An unexpected doubling in redox storage emerging from a new pincer ligand upon bis-ligation of iron(ii) is described. When tetrazine arms are present at the two ortho positions of pyridine, the resulting bis-tetrazinyl pyridine (btzp) pincer ligand displays a single one-electron reduction at ca. -0.85 V vs. Ag/AgCl. Complexation to iron, giving the cation Fe(btzp)2 2+, shows no oxidation but four reduction waves in cyclic voltammetry instead of the two expected for the two constituent ligands. Mossbauer, X-ray diffraction and NMR studies show the iron species to contain low spin Fe(ii), but with evidence of back donation from iron to the pincer ligands. CV and UV-Vis spectroelectrochemistry, as well as titration studies as monitored by CV, electronic spectra and EPR reveal the chemical reversibility of forming the reduced species. DFT and EPR studies show varying degrees of delocalization of unpaired spin in different species, including that of a btzp-1 radical anion, partnered with various cations. This journal is the Partner Organisations 2014.
Experimental and theoretical studies of a triazole ligand and complexes formed with the lanthanides
Drew, Michael G. B.,Hudson, Michael J.,Iveson, Peter B.,Madic, Charles,Russell, Mark L.
, p. 2433 - 2440 (1999)
The crystal structure of 2DBTZP·H2O [DBTZP = 2,6-bis(5-butyl-1,2,4-triazol-3-yl)pyridine] has been determined and shows a dimeric structure in which two ligands, with different protonation patterns, form four hydrogen bonds with an enclosed water molecule. Several crystal structures have been determined of lanthanide complexes with the corresponding 5-methyl derivative (DMTZP) which cover the lanthanide series. Four different structural types are reported: LaIII forms [La(DMTZP)(NO3)(H2O)5][NO3) 2; NdIII, SmIII and TbIII in the first part of the lanthanide series form [M(DMTZP)(NO3)3(H2O)] which is crystallographically disordered over a two-fold axis, HoIII forms [Ho(DMTZP)(NO3)3(H2O)], with one monodentate nitrate giving nine co-ordination, while ErIII and YbIII form [M(DMTZP)(NO3)3] complexes which are also nine-co-ordinate.
Environmentally benign and economic synthesis of covalent triazine-based frameworks
Zhang, Ling,Liu, Xue,Yang, Rui-Xia,Huang, Nian-Yu,Deng, Wei-Qiao
, p. 583 - 588 (2017)
Covalent triazine-based frameworks (CTFs) are important microporous materials with a wide range of applications. Here, we demonstrate an environmentally benign and economic synthetic pathway to CTFs. The monomers used for CTFs, aromatic nitriles, were obtained by cyanation using nontoxic potassium hexacyanoferrate(II) in place of commonly used toxic cyanides. Then, the CTFs were synthesized by trimerization of the corresponding cyano monomers in molten zinc chloride. A series of CTFs was synthesized, and the highest Brunauer-Emmett-Teller surface area measured in this series was 2404 m2/g. Among the synthesized CTFs, CTFDCP exhibited excellent CO2 adsorption properties, with a CO2 uptake of 225 mg/g at 0 °C.
Immobilized palladium nanoparticles on a cyclodextrin-polyurethane nanosponge (Pd-CD-PU-NS): An efficient catalyst for cyanation reaction in aqueous media
Khajeh Dangolani, Soheila,Sharifat, Sara,Panahi, Farhad,Khalafi-Nezhad, Ali
supporting information, p. 256 - 265 (2019/06/07)
Immobilized palladium nanoparticles on a cyclodextrin-polyurethane nanosponge (Pd-CD-PU-NS) were found to be an efficient heterogeneous catalyst in the cyanation reaction of aryl halides in aqueous media. This catalyst system is containing palladium nanoparticles with a size of ～7 nm. Moreover, the CD-PU-NS support formed microsphere-shaped structures with a size of ～100–200 nm. The TEM images show that Pd nanoparticles were formed in near spherical shape morphology and were immobilized in the structure of the CD-PU-NS support. Under our optimized reaction conditions, aryl cyanides were obtained in high yields in the presence of the Pd-CD-PU-NS catalyst. Our results demonstrated that the Pd-CD-PU-NS catalyst is highly effective in the cyanation reaction in aqueous media. Furthermore, the catalyst could be simply extracted from the reaction mixture, providing an efficient methodology for the synthesis of aryl cyanides. The Pd-CD-PU-NS catalyst could be recycled four times with almost consistent catalytic efficiency.
Pd-Metalated Conjugated Nanoporous Polycarbazoles for Additive-Free Cyanation of Aryl Halides: Boosting Catalytic Efficiency through Spatial Modulation
Ding, Shunmin,Tian, Chengcheng,Zhu, Xiang,Abney, Carter W.,Tian, Ziqi,Chen, Bo,Li, Meijun,Jiang, De-En,Zhang, Ning,Dai, Sheng
, p. 2348 - 2351 (2017/06/13)
Transition-metal-catalyzed cyanation of aryl halides is a common route to benzonitriles, which are integral to many industrial procedures. However, traditional homogeneous catalysts for such processes are expensive and suffer poor recyclability, so a heterogeneous analogue is highly desired. A novel spatial modulation approach has been developed to fabricate a heterogeneous Pd-metalated nanoporous polymer, which catalyzes the cyanation of aryl halides without need for ligands. The catalyst displays high activity in the synthesis of benzonitriles, including high product yields, excellent stability and recycling, and broad functional-group tolerance.
