02690nas a2200229   4500008004100000022001400041245011000055210006900165260000900234300001400243490000800257520190300265100002202168700001502190700002302205700001702228700002402245700002402269700001802293700002402311856012502335       2018                        eng d  a0002-786300aIron Catalyzed Hydroformylation of Alkenes under Mild Conditions: Evidence of an Fe(II) Catalyzed Process0 aIron Catalyzed Hydroformylation of Alkenes under Mild Conditions  cMAR   a4430-44390 v1403 a<p>Earth abundant, first row transition metals offer a cheap and sustainable alternative to the rare and precious metals. However, utilization of first row metals in catalysis requires harsh reaction conditions, suffers from limited activity, and fails to tolerate functional groups. Reported here is a highly efficient iron catalyzed hydroformylation of alkenes under mild conditions. This protocol operates at 10-30 bar syngas pressure below 100 degrees C, utilizes readily available ligands, and applies to an array of olefins. Thus, the iron precursor [HFe(CO)(4)](-)[Ph3PNPPh3](+) (1) in the presence of triphenyl phosphine catalyzes the hydroformylation of 1-hexene (S2), 1-octene (S1), 1-decene (S3), 1-dodecene (S4), 1-octadecene (S5), trimethoxy(vinyl)silane (S6), trimethyl(vinyl)silane (S7), cardanol (S8), 2,3-dihydrofuran (S9), allyl malonic acid (S10), styrene (S11), 4-methylstyrene (S12), 4-iBu-styrene (S13), 4-tBu-styrene (S14), 4-methoxy styrene (S15), 4-acetoxy styrene (S16), 4-bromo styrene (S17), 4-chloro styrene (S18), 4-vinylbenzonitrile (S19), 4-vinylbenzoic acid (S20), and allyl benzene (S21) to corresponding aldehydes in good to excellent yields. Both electron donating and electron withdrawing substituents could be tolerated and excellent conversions were obtained for S11-S20. Remarkably, the addition of 1 mol % acetic acid promotes the reaction to completion within 16-24 h. Detailed mechanistic investigations revealed in situ formation of an iron-dihydride complex [H2Fe(CO)(2)(PPh3)(2)] (A) as an active catalytic species. This finding was further supported by cyclic voltammetry investigations and intermediacy of an Fe(0)-Fe(II) species was established. Combined experimental and computational investigations support the existence of an iron-dihydride as the catalyst resting state, which then follows a Fe(II) based catalytic cycle to produce aldehyde.</p>1 aPandey, Swechchha1 aRaj, Vipin1 aShinde, Dinesh, R.1 aVanka, Kumar1 aKashyap, Varchaswal1 aKurungot, Sreekumar1 aVinod, C., P.1 aChikkali, Samir, H.  uhttps://library.ncl.res.in/content/iron-catalyzed-hydroformylation-alkenes-under-mild-conditions-evidence-feii-catalyzed02382nas a2200241   4500008004100000022001400041245016300055210006900218260000800287300001200295490000800307520150800315100002301823700002401846700001701870700001801887700002701905700001901932700001701951700002401968700002101992856012702013       2019                        eng d  a0008-622300aIn-situ generated Mn3O4-reduced graphene oxide nanocomposite for oxygen reduction reaction and isolated reduced graphene oxide for supercapacitor applications0 aInsitu generated Mn3O4reduced graphene oxide nanocomposite for o  cDEC  a285-2910 v1543 a<p>We have generated in situ nanocomposite of Mn3O4 and reduced graphene oxide (rGO) upon employing wet-chemical reduction of graphene oxide (GO) by Mn(II) salt as mild-reducing agent for the first time and examined the oxygen reduction reaction (ORR) activity in 0.1 M KOH electrolyte. The half-wave potential (E-1/2) of the nanocomposite catalyst (20% Mn3O4-rGO/C) was found to be around -0.153 V which is only similar to 87 mV negative from the commercially available catalyst (20% Pt/C). Remarkably, after 5000 linear sweep voltammetry cycles the E-1/2 shifted marginally by 20 mV; and the number of electrons transferred during ORR was estimated to be close to 4. Such an efficient electrocatalytic performance of the nanocomposite was primarily attributed to the synergistic interaction between Mn3O4 and rGO. The fabricated all-solid-state supercapacitor of rGO (extracted from the nanocomposite) in aqueous polyvinyl alcohol-sulfuric acid (PVA-H2SO4) gel polymer electrolyte (GPE) showed C-s value of similar to 310 F/g at a current density of 1 A/g along with long durability (10,000 charge-discharge cycles). All-solid-state flexible rGO supercapacitor exhibited high-flexibility and excellent durability (30,000 cycles with 100% retention of C-s). Our results provide an enormous opportunity in designing transition metal oxides decorated semiconducting reduced graphene oxide nanocomposite platforms for various electrochemical applications. (C) 2019 Elsevier Ltd. All rights reserved.</p>
1 aJha, Plawan, Kumar1 aKashyap, Varchaswal1 aGupta, Kriti1 aKumar, Vikash1 aDebnath, Anil, Krishna1 aRoy, Debashree1 aRana, Shammi1 aKurungot, Sreekumar1 aBallav, Nirmalya  uhttps://library.ncl.res.in/content/situ-generated-mn3o4-reduced-graphene-oxide-nanocomposite-oxygen-reduction-reaction-and