https://www.selleckchem.com/products/n-acetyl-dl-methionine.html Three synthetic methods towards semi-planar triarylboranes with two aryl rings connected by a methylene bridge have been developed. The fine-tuning of their stereoelectronic properties and Lewis acidities was achieved by introducing fluorine, methyl, methoxy, n-butyl and phenyl groups either at their exocyclic or bridged aryl rings. X-ray diffraction analysis and quantum-chemical calculations provided quantitative information on the structural distortion experienced by the near planar hydro-boraanthracene skeleton during the association with Lewis bases such as NH3 and F- . Though the methylene bridge between the ortho-positions of two aryl rings of triarylboranes decreased the Gibbs free energies of complexation with small Lewis bases by less than 5 kJ mol-1 relative to the classical Lewis acid BAr3 , the steric shielding of the CH2 bridge is sufficient to avoid the formation of Lewis adducts with larger Lewis bases such as triarylphosphines. A newly synthesized spirocyclic amino-borane with a long intramolecular B-N bond that could be dissociated under thermal process, UV-irradiation, or acidic conditions might be a potential candidate in Lewis pairs catalysis. This retrospective study aims to quantify the early impact of the COVID-19 pandemic on trauma and orthopaedic surgery at a Major Trauma Centre (MTC) in the United Kingdom. We hypothesise that the social restrictions placed on the public by the government will reduce the amount of trauma presentations and operations performed. A database of all trauma patients at the MTC was retrospectively reviewed from start of social restrictions on 16 March 2020, to 22nd April 2020 inclusive. Referrals to the orthopaedic team were identified and included; these were sub-classified into major trauma patients, fragility hip fractures and paediatric trauma. All patients undergoing surgical intervention were identified. The outcome measures were the total numbe