Metal–ligand Lability and Ligand Mobility Enables Framework Transformation via Ligand Release in a Family of Crystalline 2D Coordination Polymers. Issue 51 (19th July 2022)

• Record Type: Journal Article
• Authors: Lang, Feifan; Singh, Daljit C. N. G.; Rao, Abhishek B.; Romer, Catherine; Wright, James S.; Smith, Rebecca; Adams, Harry; Brammer, Lee
• Is Part Of: Chemistry. Volume 28:Issue 51(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-19
• Subjects: coordination polymer -- crystal engineering -- dielectric constant -- in situ X-ray diffraction -- solid-state reaction; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202201408
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A family of seven silver(I)‐perfluorocarboxylate‐quinoxaline coordination polymers, [Ag4 (O2 CRF )4 (quin)4 ] 1 –5 (RF =(CF2 )n‐1 CF3 )4, n=1 to 5); [Ag4 (O2 C(CF2 )2 CO2 )2 (quin)4 ] 6 ; [Ag4 (O2 CC6 F5 )4 (quin)4 ] 7 (quin=quinoxaline), denoted by composition as 4 : 4 : 4 phases, was synthesised from reaction of the corresponding silver(I) perfluorocarboxylate with excess quinoxaline. Compounds 1 –7 adopt a common 2D layered structure in which 1D silver‐perfluorcarboxylate chains are crosslinked by ditopic quinoxaline ligands. Solid‐state reaction upon heating, involving loss of one equivalent of quinoxaline, yielding new crystalline 4 : 4 : 3 phases [Ag4 (O2 C(CF2 )n‐1 CF3 )4 (quin)3 ]n (8 –10, n=1 to 3), was followed in situ by PXRD and TGA studies. Crystal structures were confirmed by direct syntheses and structure determination. The solid‐state reaction converting 4 : 4 : 4 to 4 : 4 : 3 phase materials involves cleavage and formation of Ag−N and Ag−O bonds to enable the structural rearrangement. One of the 4 : 4 : 3 phase coordination polymers (10 ) shows the remarkably high dielectric constant in the low electric field frequency range. Abstract : Two‐dimensional coordination polymers exhibit ligand extrusion into the vapour phase on heating to undergo an extensive structural reorganisation involving bond breaking and formation, ligand migration and reorientation. The reactions occur with retention of crystallinity and have been followed in situ by PXRD.