TY - JOUR
T1 - Coordination-driven self-assembly, structures, and dynamic properties of diplatinum hexatriynediyl and butadiynediyl complexes in which the sp carbon chains are shielded by sp3 carbon chains
T2 - Towards endgroup-endgroup interactions
AU - Owen, Gareth R.
AU - Stahl, Jürgen
AU - Hampel, Frank
AU - Gladysz, John A.
PY - 2008/1/18
Y1 - 2008/1/18
N2 - Sequential reactions of trans(C6F5)(p-tol 3P)2Pt(C≡C)3SiEt3 (PtC 6-SiEt3) with nBu4N+ F- (THF/methanol), PtCl, KPF6/tBuOK, and CuCl give trans,trans-[(C 6F5){(p-tol3P)2}Pt(C≡ C) 3Pt{(Pp-tol3)2}(C6F5)] (PtC6Pt) in 95% yield on multigram scales. Reactions of PtC 6Pt and Ar2P(CH2)mPAr2 afford substitution products trans,trans-[(C6F5){(Ar 2P(CH2)mPAr2)}Pt(C≡C) 3Pt{(Ar2P(CH2)mPAr 2)}(C6F5)] (PtC6Pt-m/Ar; m/Ar = 8/p-tol, 78%; 10/Ph, 82%; 11/Ph, 69%; 12/Ph, 57%; 14/p-tol, 57%; 14/p-C 6H4-tBu, 71%), in which the diphosphines span the square planar platinum endgroups. An analogous reaction with PEt3 gives a tetrakis PEt3 complex Pt′C6Pt′ (72%). The crystal structures of PtC6Pt, Pt′C6Pt′, PtC6Pt-10/Ph, PtC6Pt-11/Ph, and PtC6Pt-14/p-tol or solvates thereof are compared. In PtC6Pt, the endgroups can avoid van der Waals contact, and define angles of 0°. In PtC6Pt-14/p- tol, the sp3 chains twist around the sp chain in a chiral double-helical motif, with an endgroup/endgroup angle of 189°. The sp 3 chains are too short to adopt analogous conformations in the other complexes, but laterally shield the sp chain. NMR spectroscopy shows that the helical enantiomers of PtC6Pt-14/p-tol rapidly interconvert in solution at low temperature. A crystal structure of PtC4Pt shows endgroups that are in van der Waals contact and define an angle of 41°. Reactions with Ar2P-(CH2)8PAr2 give PtC4Pt-8/Ar (Ar = Ph, 53%; p-tol, 87%). Low-temperature NMR spectroscopy establish non-helical chiral conformations. Electrochemical oxidations of the diplatinum complexes are analyzed, the reversibilities of which decrease with increasing sp chain length.
AB - Sequential reactions of trans(C6F5)(p-tol 3P)2Pt(C≡C)3SiEt3 (PtC 6-SiEt3) with nBu4N+ F- (THF/methanol), PtCl, KPF6/tBuOK, and CuCl give trans,trans-[(C 6F5){(p-tol3P)2}Pt(C≡ C) 3Pt{(Pp-tol3)2}(C6F5)] (PtC6Pt) in 95% yield on multigram scales. Reactions of PtC 6Pt and Ar2P(CH2)mPAr2 afford substitution products trans,trans-[(C6F5){(Ar 2P(CH2)mPAr2)}Pt(C≡C) 3Pt{(Ar2P(CH2)mPAr 2)}(C6F5)] (PtC6Pt-m/Ar; m/Ar = 8/p-tol, 78%; 10/Ph, 82%; 11/Ph, 69%; 12/Ph, 57%; 14/p-tol, 57%; 14/p-C 6H4-tBu, 71%), in which the diphosphines span the square planar platinum endgroups. An analogous reaction with PEt3 gives a tetrakis PEt3 complex Pt′C6Pt′ (72%). The crystal structures of PtC6Pt, Pt′C6Pt′, PtC6Pt-10/Ph, PtC6Pt-11/Ph, and PtC6Pt-14/p-tol or solvates thereof are compared. In PtC6Pt, the endgroups can avoid van der Waals contact, and define angles of 0°. In PtC6Pt-14/p- tol, the sp3 chains twist around the sp chain in a chiral double-helical motif, with an endgroup/endgroup angle of 189°. The sp 3 chains are too short to adopt analogous conformations in the other complexes, but laterally shield the sp chain. NMR spectroscopy shows that the helical enantiomers of PtC6Pt-14/p-tol rapidly interconvert in solution at low temperature. A crystal structure of PtC4Pt shows endgroups that are in van der Waals contact and define an angle of 41°. Reactions with Ar2P-(CH2)8PAr2 give PtC4Pt-8/Ar (Ar = Ph, 53%; p-tol, 87%). Low-temperature NMR spectroscopy establish non-helical chiral conformations. Electrochemical oxidations of the diplatinum complexes are analyzed, the reversibilities of which decrease with increasing sp chain length.
KW - Helical structures
KW - NMR spectroscopy
KW - Platinum
KW - Self-assembly
KW - Structure elucidation
U2 - 10.1002/chem.200701268
DO - 10.1002/chem.200701268
M3 - Article
AN - SCOPUS:38049102765
SN - 0947-6539
VL - 14
SP - 73
EP - 87
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 1
ER -