2, 6‐(Diphenylmethyl)‐Aryl‐Substituted Neutral and Anionic Phosphates: Approaches to H‐Bonded Dimeric Molecular Structures. Issue 28 (5th October 2017)

• Record Type: Journal Article
• Authors: Mandal, Debdeep; Santra, Biswajit; Kalita, Pankaj; Chrysochos, Nicolas; Malakar, Amit; Narayanan, Ramakirushnan Suriya; Biswas, Sourav; Schulzke, Carola; Chandrasekhar, Vadapalli; Jana, Anukul
• Is Part Of: ChemistrySelect. Volume 2:Issue 28(2017)
• Page Start: 8898
• Page End: 8910
• Publication Date: 2017-10-05
• Subjects: hydrogen bonds -- phosphorus -- solid state structures -- solvent effects -- zinc; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201701133
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: 2, 6‐(Diphenylmethyl)‐4‐alkyl‐phenyl substituted phosphates, ArOP(O)(OH)2 (Ar=2, 6‐CHPh2 ‐4‐R‐C6 H2 ; R=Me (9 ), Et (10 ), i Pr (11 ), and t Bu (12 )), were synthesized from the corresponding phenols. The single crystals of these compounds were obtained from their solutions of CH3 CN or CH3 COCH3 . The molecular structures of these compounds, in the solid state, determined by single crystal X‐ray analysis reveal that they possess a hitherto unknown structural motif among monoorganophosphate esters viz., a dimeric hydrogen bonded structure involving a P−OH donor and a P=O acceptor group affording an eight‐membered ring. This structural motif is similar to what is commonly found in the solid state structures of carboxylic acids. In all of these compounds the solid state structure is restricted to the dimeric motif except in9 where a 1D hydrogen‐bonded polymer formation is observed when it crystallized from acetonitrile. Deprotonation of these monoorganophosphates with triethylamine afforded the anionic phosphates, [ArOP(O)(OH)(O)] − containing Et3 NH + as the counter cation (Ar=2, 6‐CHPh2 ‐4‐R‐C6 H2 ; R=Me (13 ), Et (14 ), i Pr (15 ), and t Bu (16 )). The solid state molecular structures of13–16 again reveal hydrogen‐bonded dimeric structures in the solid state. In order to demonstrate the proof‐of‐principle with regard to the reactivity of the monoorganophosphates, we explored the reaction of9 with ZnCl2 in the presence of pyrazole (PzH) and Et3 N affording a dinuclear Zn(II) complex, [Et3 NH]2 [{ArOP(O)3 }2 {Zn(Cl)(PzH)}2 ] (Ar=2, 6‐CHPh2 ‐4‐Me–C6 H2 ) (17 ). The two Zn(II) centers are linked to each other by two dianionic [ArOP(O)3 ] 2− ligands. Two additional triethylammonium cations and a terminal Zn−Cl moiety compensate the charge and complete the composition of17 . Abstract : Phosphate monoesters and their monoanions containing sterically hindered substituents were shown to possess dimeric hydrogen‐bonded structures in the solid state, assisted by solvent/counter cation participation in the hydrogen‐bonding. A dinuclear eight‐membered zinc phosphate has also been isolated and characterized.