Bridging the Gap: Attractive 3c–4e Interactions in peri‐Substituted Acenaphthylenes. Issue 9 (24th February 2014)

• Record Type: Journal Article
• Authors: Diamond, Louise M.; Knight, Fergus R.; Athukorala Arachchige, Kasun S.; Randall, Rebecca A. M.; Bühl, Michael; Slawin, Alexandra M. Z.; Woollins, J. Derek
• Is Part Of: European journal of inorganic chemistry. Issue 9(2014)
• Page Start: 1512
• Page End: 1523
• Publication Date: 2014-02-24
• Subjects: Arenes -- Fused‐ring systems -- Noncovalent interactions -- Density functional calculations -- Chalcogens; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201301549
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: A series of peri ‐substituted acenaphthylenes that contain mixed halogen–chalcogen functionalities at the 5, 6‐positions in1 –6 [Acenapyl[X](EPh) (Acenapyl = acenaphthylene‐5, 6‐diyl; X = Br, I; E = S, Se, Te)] and chalcogen–chalcogen moieties in7 –11 [Acenap(EPh)(E′Ph) (Acenap = acenaphthene‐5, 6‐diyl; E/E′ = S, Se, Te)] have been prepared from their corresponding acenaphthene analoguesA1 –A11 by utilising 2, 3‐dichloro‐5, 6‐dicyano‐1, 4‐benzoquinone (DDQ) for the dehydrogenation of the ethane backbone. The related dihalide compounds13 and14 Acenapyl[XX′] (XX′ = BrBr, II) have also been prepared by following a similar procedure, and 1, 2, 5, 6‐tetrabromo‐1, 2‐dihydroacenaphthyleneA0 was prepared as an intermediate by following an alternative route to13 . The series of acenaphthylene compounds have remarkably similar molecular structures to their acenaphthene counterparts; they exhibit an expected increase in peri separation as heavier congeners occupy the close peri positions. The presence of the ethene bridge, however, naturally compresses the nearest bay angle as it increases the splay of the exocyclic peri atoms, thereby resulting in a minor increase in separation relative to equivalent acenaphthenes. The structures of1 –11, 13 and14 are discussed and compared with previously reported analogous naphthalene and acenaphthene compounds. Similar to acenaphthene derivatives, aromatic ring conformations and the location of p ‐type lone pairs influences the geometry of the peri region. Under appropriate geometric conditions, quasi‐linear three‐body CPh –E··· Z (E = Te, Se, S; Z = Br/E) fragments provide an attractive component for the E··· Z interaction. DFT studies confirm the onset of formation of three‐center, four‐electron bonding, similar in extent to that observed in analogous acenaphthenes, despite an increase in the peri distances. Abstract : peri ‐Substituted acenaphthylenes [Acenapyl(X)(EPh)] and [Acenapyl(EPh)(E′Ph)] have been prepared and molecular structures determined where possible. Comparison with analogous naphthalene and acenaphthene compounds reveals similar trends. Under appropriate geometric conditions, quasilinear CPh –E··· Z (E = Te, Se, S; Z = Br/E) fragments exist to promote attractive 3c–4e interactions.