sp carbon chains surrounded by sp3 carbon double helices: Coordination-driven self-assembly of wirelike Pt(C≡C)nPt moieties that are spanned by two P(CH2)mP linkages

Jürgen Stahl, Wolfgang Mohr, Laura De Quadras, Thomas B. Peters, James C. Bohling, José Miguel Martín-Alvarez, Gareth R. Owen, Frank Hampel, John A. Gladysz*

*Awdur cyfatebol y gwaith hwn

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

74 Dyfyniadau (Scopus)

Crynodeb

Reactions of trans, trans-(C6F5)(p-tol 3P)2Pt(C≡C)4Pt(Pp-tol3) 2(C6F5) and diphosphines Ar 2P(CH2)m-PAr2 yield trans,trans-(C6F5)(Ar2P(CH2) mPAr2)Pt(C≡C)4Pt(Ar2P(CH 2)mPAr2)(C6F5), in which the platinum atoms are spanned via an sp and two sp3 carbon chains (Ar/m = 3, Ph/14, 87%; 4, p-tol/14, 91%; 5, p-C6H4-t-Bu/ 14, 77%; 7, Ph/10, 80%; 8, Ph/11, 80%; 9, Ph/12, 36%; only oligomers form for m > 14). Crystal structures of 3-5 show that the sp3 chains adopt chiral double-helical conformations that shield the sp chain at approximately the van der Waals distance, with both enantiomers in the unit cell. The platinum square planes define angles of 196.6°-189.9° or more than a half twist. Crystal structures of 7-9, which have shorter sp3 chains, exhibit nonhelical conformations. Reaction of the corresponding Pt-(C≡C) 6Pt complex and Ph2P(CH2)18PPh 2 gives an analogous adduct (27%). The crystal structure shows two independent molecules, one helical and the other not. Low-temperature NMR data suggest that the enantiomeric helical conformations of 3-5 rapidly interconvert in solution. Cyclic voltammograms of 3-5 show more reversible oxidations than model compounds lacking bridging sp3 chains. These are the only double-helical molecules that do not feature bonding interactions between the helix strands, or covalent bonds to templates dispersed throughout the strands, or any type of encoding. The driving force for helix formation is analyzed.

Iaith wreiddiolSaesneg
Tudalennau (o-i)8282-8295
Nifer y tudalennau14
CyfnodolynJournal of the American Chemical Society
Cyfrol129
Rhif cyhoeddi26
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - 4 Gorff 2007
Cyhoeddwyd yn allanolIe

Ôl bys

Gweld gwybodaeth am bynciau ymchwil 'sp carbon chains surrounded by sp3 carbon double helices: Coordination-driven self-assembly of wirelike Pt(C≡C)nPt moieties that are spanned by two P(CH2)mP linkages'. Gyda’i gilydd, maen nhw’n ffurfio ôl bys unigryw.

Dyfynnu hyn