Direct synthesis of partially ethoxylated branched polyethylenimine from ethanolamine.

We report here a method to make a branched and partially ethoxylated polyethyleneimine derivative directly from ethanolamine. The polymerization reaction is catalysed by a pincer complex of Earth-abundant metal, manganese, and produces water as the only byproduct. Industrial processes to produce polyethyleneimines involve the transformation of ethanolamine to a highly toxic chemical, aziridine, by an energy-intensive/waste-generating process followed by the ring-opening polymerization of aziridine.

Dehydropolymerization of Amine-Boranes using Bis(imino)pyridine Rhodium Pre-Catalysis: σ-Amine-Borane Complexes, Nanoparticles, and Low Residual-Metal BN-Polymers that can be Chemically Repurposed.

The sigma amine-borane complexes [Rh(L1)(η :η -H B⋅NRH )][OTf] (L1=2,6-bis-[1-(2,6-diisopropylphenylimino)ethyl]pyridine, R=Me, Et, Pr) are described, alongside [Rh(L1)(NMeH )][OTf]. Using R=Me as a pre-catalyst (1 mol %) the dehydropolymerization of H B ⋅ NMeH gives [H BNMeH] selectively. Added NMeH , or the direct use of [Rh(L1)(NMeH )][OTf], is required for initiation of catalysis, which is suggested to operate through the formation of a neutral hydride complex, Rh(L1)H.

Manganese catalysed dehydrogenative synthesis of polyureas from diformamide and diamines.

We report here the synthesis of polyureas from the dehydrogenative coupling of diamines and diformamides. The reaction is catalysed by a manganese pincer complex and releases H gas as the only by-product making the process atom-economic and sustainable. The reported method is greener in comparison to the current state-of-the-art production routes that involve diisocyanate and phosgene feedstock.

Synthesis of Polyethyleneimines from the Manganese-Catalysed Coupling of Ethylene Glycol and Ethylenediamine.

Polyethyleneimines find many applications in products such as detergents, adhesives, cosmetics, and for processes such as tissue culture, gene therapy, and CO capture. The current state-of-the-art technology for the production of the branched polyethyleneimines involves aziridine feedstock which is a highly toxic, volatile and mutagenic chemical and raises significant concern to human health and environment. We report here a novel method for the synthesis of branched polyethyleneimine derivative from ethylene glycol and ethylenediamine which are much safer, environmentally benign, commercially available and potentially renewable feedstock.

Dehydropolymerization of HB·NMeH Mediated by Cationic Iridium(III) Precatalysts Bearing κ- Pr-PN P Pincer Ligands ( = H, Me): An Unexpected Inner-Sphere Mechanism.

The dehydropolymerization of HB·NMeH to form -methylpolyaminoborane using neutral and cationic catalysts based on the {Ir( Pr-PNP)} fragment [ Pr-PNP = κ-(CHCHP Pr)NH] is reported. Neutral Ir( Pr-PNP)H or Ir( Pr-PNP)HCl precatalysts show no, or poor and unselective, activity respectively at 298 K in 1,2-FCH solution. In contrast, addition of [NMeH][BAr ] (Ar = 3,5-(CF)CH) to Ir( Pr-PNP)H immediately starts catalysis, suggesting that a cationic catalytic manifold operates.

Versatile, Cheap, Readily Modifiable Sample Delivery Method for Analysis of Air-/Moisture-Sensitive Samples Using Atmospheric Pressure Solids Analysis Probe Mass Spectrometry.

A cheap, versatile, readily modified, and reusable glass probe system enabling delivery of solid air-/moisture-sensitive samples for mass spectrometric (MS) analysis using an Atmospheric pressure Solids Analysis Probe (ASAP) is described. The simplicity of the design allows quick and easy ASAP MS analyses of sensitive solid and liquid samples without the need for any modifications to commercially available vertically loaded ASAP mass spectrometers. A comparison of ASAP mass spectra obtained for metal complexes under air and an inert atmosphere is given.

Controlled Synthesis of Well-Defined Polyaminoboranes on Scale Using a Robust and Efficient Catalyst.

The air tolerant precatalyst, [Rh(L)(NBD)]Cl () [L = κ-(PrPCHCH)NH, NBD = norbornadiene], mediates the selective synthesis of -methylpolyaminoborane, (HBNMeH), by dehydropolymerization of HB·NMeH. Kinetic, speciation, and DFT studies show an induction period in which the active catalyst, Rh(L)H (), forms, which sits as an outer-sphere adduct as the resting state. At the end of catalysis, dormant Rh(L)HCl () is formed.

η-Alkene Complexes of [Rh(PONOP-Pr)(L)] Cations (L = COD, NBD, Ethene). Intramolecular Alkene-Assisted Hydrogenation and Dihydrogen Complex [Rh(PONOP-Pr)(η-H)].

Rhodium-alkene complexes of the pincer ligand κ-CHN-2,6-(OPPr) (PONOP-Pr) have been prepared and structurally characterized: [Rh(PONOP-Pr)(η-alkene)][BAr] [alkene = cyclooctadiene (COD), norbornadiene (NBD), ethene; Ar = 3,5-(CF)CH]. Only one of these, alkene = COD, undergoes a reaction with H (1 bar), to form [Rh(PONOP-Pr)(η-COE)][BAr] (COE = cyclooctene), while the others show no significant reactivity. This COE complex does not undergo further hydrogenation.