Highly productive CO2 hydrogenation to methanol - a tandem catalytic approach via amide intermediates.

A new system for CO2 reduction to methanol has been demonstrated using homogeneous ruthenium catalysts with a range of amine auxiliaries. Modification of this amine has a profound effect on the yield and selectivity of the reaction. A TON of 8900 and TOF of 4500 h-1 is achieved using a [RuCl2(Ph2PCH2CH2NHMe)2] catalyst with a diisopropylamine auxiliary.

Synthesis of chelating diamido Sn(IV) compounds from oxidation of Sn(II) and directly from Sn(IV) precursors.

Three dimethyltindiamides containing chelating diamide ligands were synthesised from the reaction of the dilithiated diamine and Me2SnCl2; [SnMe2(L1)] 1 (L1 = κ(2)-N(Dipp)C2H4N(Dipp)), [SnMe2(L2)] 2 (L2 = κ(2)-N(Dipp)C3H6N(Dipp)) and [SnMe2(L3)] 3 (L3 = κ(2)-N(Dipp)SiPh2N(Dipp)), Dipp = 2,6-(i)Pr2C6H3. Reaction of (L2)H2 with SnCl4 and NEt3 led to the formation of the diamidotin dichloride [SnCl2(L2)] 4 whereas reaction of (L1)H2 with SnCl4 and NEt3, or [Sn(L1)] with SnCl4, led to the exclusive formation of the amidotin trichloride [SnCl3{κ(2)-DippN(H)C2H4N(Dipp)}] 5. Reactions of [Sn(L1)] with sulfur and selenium formed [{Sn(L1)(µ-E)}2] (E = S 10 and Se )11. MeI reacted with N-heterocyclic stannylenes to generate the Sn(iv) addition products [Sn(Me)I(L1)] 12, [Sn(Me)I(L2)] 13, [Sn(Me)I(L3)] 14 and [Sn(Me)I(L4)] 15 (L4 = κ(3)-N(Dipp)C2H4OC2H4N(Dipp)), and subsequent reaction with AgOTf (OTf = OSO2CF3) generated the corresponding Sn(iv) triflates [Sn(Me)OTf(L1)] 16, [Sn(Me)OTf(L2)] 17 and [Sn(Me)OTf(L4)] 19 with [Sn(Me)OTf(L3)] 18 formed only as a mixture with unidentified by-products. All of the compounds were characterised by single crystal X-ray diffraction.

The nature of the active species in bis(imino)pyridyl cobalt ethylene polymerisation catalysts.

Studies on cobalt ethylene polymerisation catalysts bearing bis(imino)pyridine ligands strongly indicate that the activated species is not the anticipated cobalt(II) alkyl cation.