01458nas a2200217 4500008004100000022001400041245013200055210006900187260007500256300001400331490000600345520063000351653001200981653002000993653002101013653001801034653001201052100002201064700002401086856013001110 2015 eng d a1867-388000aHighly regioselective isomerizing hydroformylation of long-chain internal olefins catalyzed by a rhodium bis(phosphite) complex0 aHighly regioselective isomerizing hydroformylation of longchain  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a3468-34710 v73 a

The single-step synthesis, coordination behavior, and application of a bis(phosphite) ligand in the isomerizing hydroformylation of internal olefins was investigated. Interestingly, high-pressure NMR spectroscopy investigations revealed unexpected inequivalency of the two phosphorus nuclei, which display bisequatorial coordination of the bis(phosphite) ligand in a trigonal bipyramidal rhodium complex. Upon employment in the isomerizing hydroformylation of the exceedingly challenging plant oil derived substrate methyl oleate, the bis(phosphite) rhodium complex revealed an unprecedented linear selectivity of 75%.

10aalkenes10abis(phosphite)s10aHydroformylation10aisomerization10aRhodium1 aPandey, Swechchha1 aChikkali, Samir, H. uhttps://library.ncl.res.in/content/highly-regioselective-isomerizing-hydroformylation-long-chain-internal-olefins-catalyzed-001970nas a2200241 4500008004100000022001400041245013700055210006900192260000800261300001600269490000600285520111900291653002101410653001301431653001201444653001801456653002201474100002301496700002301519700002501542700002901567856013201596 2020 eng d a2365-654900aCooperative acid-base sites of solid Ba-Zr mixed oxide catalyst for efficient isomerization of glucose to fructose in aqueous medium0 aCooperative acidbase sites of solid BaZr mixed oxide catalyst fo cOCT a12505-125130 v53 a

Efficient and highly selective isomerization of glucose to fructose was achieved by using the inexpensive Ba-Zr mixed metal oxide catalyst. Catalyst was prepared by varying Ba-Zr ratios using co-precipitation method. Various phases formed, planes exposed, morphology, elemental composition and particle size, basic site density and strength, oxidation state of elements were well studied by using various characterization techniques. The XRD analysis clearly indicates the presence of Ba+2 and Zr+4 in the form of BaO, ZrO2 and BaZrO3 phases. The SEM and HR-TEM images indicate that, Ba-Zr (2 : 1) catalyst prepared showed uniform morphology with spherical and rod-shaped particles ranging from 300 to 600 nm. Under the optimized reaction conditions Ba-Zr (2 : 1) catalyst exhibited excellent results in terms of 57 % of glucose conversion with 89 % selective formation of glucose. The presence of both acidic as well as basic sites play vital roles in activating the substrate molecules to selectively yield fructose. Ba-Zr (2 : 1) catalyst showed excellent recyclability performance up to four recycles.

10aCo-precipitation10afructose10aglucose10aisomerization10amixed metal oxide1 aShaikh, Samrin, S.1 aPatil, Chetana, R.1 aKondawar, Sharda, E.1 aRode, Chandrashekhar, V. uhttps://library.ncl.res.in/content/cooperative-acid-base-sites-solid-ba-zr-mixed-oxide-catalyst-efficient-isomerization-glucose02491nas a2200253 4500008004100000022001400041245014200055210006900197260000800266300001100274490000800285520163000293653001501923653001201938653001701950653001801967653001101985100002601996700002202022700002102044700002602065700002602091856012002117 2022 eng d a0921-510700aComparative investigation on the catalytic performance of HT/SBA-15 and SBA-15/HT composites for the isomerization of glucose to fructose0 aComparative investigation on the catalytic performance of HTSBA1 cDEC a1160520 v2863 a

Hydrotalcites (HT) have a broad spectrum of applications as prosperous heterogeneous catalysts for diverse chemical transformations. The catalytic activity of HT-based materials can be tailored by introducing siliceous material into the internal or external framework. The surface modification of the HT framework with silica mesostructures leads to the formation of versatile Lewis base, Bronsted base and redox catalytic active sites. This work presents the comparative evaluation of the catalytic performance of HT/SBA-15 and SBA-15/HT composites for the isomerization of glucose to fructose using 1-butanol as a solvent. The composites with different external morphology were prepared by a modified template-assisted hydrothermal method, using different HT to SBA-15 proportions. The textural and morphological characterization results conferred the efficiency of the employed post-synthetic intercalation strategy to achieve the successful formation of HT/SBA-15 and SBA-15/HT composites. With optimal HT loading and surface basicity, the HTS-3 composite demonstrated the highest catalytic performance, resulting in good glucose conversions (54 %) with improved selectivity (>83 %). The observed high reactivity could be mainly attributed to the extensive dispersion of HT particles on the SBA-15 component, which contributes to a significant increase in textural properties and surface basicity. Furthermore, special attention is devoted to addressing such reactivity phenomena as active site selectivity, catalyst multifunctionality and multisite reactivity commonly encountered in mesoporous catalysis.

10acomposites10aglucose10ahydrotalcite10aisomerization10aSBA-151 aManikandan, Marimuthu1 aArjunan, Ayyappan1 aPrabu, Marimuthu1 aRaja, Thirumalaiswamy1 aSangeetha, Palanivelu uhttps://library.ncl.res.in/content/comparative-investigation-catalytic-performance-htsba-15-and-sba-15ht-composites02512nas a2200265 4500008004100000022001400041245010800055210006900163260000800232300001100240490000800251520162600259653001801885653001401903653002001917653001801937653002301955653002601978100002302004700002102027700001702048700002602065700002502091856013002116 2022 eng d a0022-328X00aReactivity of four coordinate iridium complex towards hydrogen: an experimental and computational study0 aReactivity of four coordinate iridium complex towards hydrogen a cMAY a1223170 v9653 a

Reaction of a four coordinate, 16-electron Ir complex, [Ir-(iPr)4(POCOP)(PPh3)] (4 ) (((iPr)4)(POCOP= 2,6-bis(di-isopropyl phosphinito)benzene, kappa(3)-C6H3-1,3-[OP((iPr))(2)](2)), with H-2 resulted in an oxidative addition product, cis-dihydride complex, cis-[Ir(H)(2) ((iPr)4)(POCOP)(PPh3)] ( cis-5 ) presumably via the intermediacy of a sigma complex, [Ir(eta(2)-H-2)((iPr)4)(POCOP)(PPh3)]. The cis-dihydride complex completely isomerizes to the trans-dihydride complex trans-[Ir(H)(2) ((iPr)4)(POCOP)(PPh3)] ( trans-5 ) under ambient conditions in about 3 h. It was found that the steric and electronic features on the iridium center have significant influence on the approach of H-2 onto the metal center followed by oxidative addition and isomerization. The isomerization process was studied in detail and all the mechanistic aspects have been elucidated using a combination of both experimental work and computation. The cis-dihydride complex isomerizes to the trans-dihydride by compensating the trans influence of the strongly trans-directing hydride ligand. A mechanism involving the exchange of the position of PPh3 with a hydride ligand cis to itself via PPh3 dissociation and re-coordination thereby resulting in the formation of the trans-dihydride complex, has been proposed for the isomerization. The cis-dihydride was found to be a highly active catalyst for hydrogenation of ethy-lene. A competing reactivity study of cis-dihydride between isomerization versus insertion of C2H4 into the Ir-H bond, was studied experimentally and computationally. (c) 2022 Elsevier B.V. All rights reserved.

10aHydrogenation10aInsertion10airidium complex10aisomerization10aOxidative addition10aReductive elimination1 aAgrawal, Nisha, K.1 aDash, Soumya, R.1 aVanka, Kumar1 aNethaji, Munirathinam1 aJagirdar, Balaji, R. uhttps://library.ncl.res.in/content/reactivity-four-coordinate-iridium-complex-towards-hydrogen-experimental-and-computational