Synthese, Struktur und Wirt-Gast-Untersuchungen an selbstorganisierten, wasserlöslichen und wasserunlöslichen mehrfach verbrückten Platinacyclophanen

Abstract

The synthesis of the 1,3,5-tris[(diphenylphosphoryl)alkyl]benzenes 7 - 10 succeeds by reaction of the corresponding 1,3,5-tris(bromoalkyl)benzenes 3 - 6 with ethyl diphenylphosphinite in an Arbusov-type reaction. Reduction of these phosphine oxides leads to the trifunctional phosphine ligands 11 - 14. Their potency of self-assembly was examined by the employment of platinum(II) complex fragments. A five-component self-assembly consisting of three equivalents of the platinum complex PtCl2(PhCN)2 and two equivalents of the ligands 11 - 14 under high dilution conditions led to the formation of the triplatinacyclophanes 1 and 15 - 17. In contrast to the reaction between 11 - 13 and PtCl2(PhCN)2 in which polymers were formed as by-products, in the case of 14 three other platinacyles 18 - 20 with a chain-like structure were formed. Trifunctional primary phosphines of the type 1,3,5-[PH2(CH2)n]3C6H3 (26 - 28) were obtained via an Arbusov reaction between the 1,3,5-tris(bromoalkyl)benzenes 3 - 6 and P(OEt)3 followed by a reaction of the trisphosphonates 1,3,5-[(EtO)2P(O)(CH2)n]3C6H3 (21 - 24) with LiAlH4. A straightforward conversion of these sensitive key phosphines 26 - 28 to the corresponding water-soluble ligands 1,3,5-tris-[bis(hydroxymethyl)phosphinylalkyl]benzenes 29 - 31 and 1,3,5-tris[bis(2'-diethylphosphona-toethyl)phophinylalkyl]benzenes 32 - 34 was achieved by formylation with formaldehyde and hydrophosphonation with diethyl vinylphosphonate, respectively. A five component self-assembly consisting of three equivalents of the platinum(II) complex Cl2Pt(NCPh)2 and two equivalents of the ligands 32 - 34 under high dilution conditions resulted in the formation of the nanoscaled, water-soluble triplatinacyclophanes 35 - 37 in high yields.

The structures of the metallacycles 1, 15 - 17 and 35 - 37 as well as 18 - 20 were elucidated by 31P{1H}, 13C{1H}, and 195Pt{1H} NMR spectroscopic investigations.

The synthesis of the 1,3,5-tris[(diphenylphosphoryl)alkyl]benzenes 7 - 10 succeeds by reaction of the corresponding 1,3,5-tris(bromoalkyl)benzenes 3 - 6 with ethyl diphenylphosphinite in an Arbusov-type reaction. Reduction of these phosphine oxides leads to the trifunctional phosphine ligands 11 - 14. Their potency of self-assembly was examined by the employment of platinum(II) complex fragments. A five-component self-assembly consisting of three equivalents of the platinum complex PtCl2(PhCN)2 and two equivalents of the ligands 11 - 14 under high dilution conditions led to the formation of the triplatinacyclophanes 1 and 15 - 17. In contrast to the reaction between 11 - 13 and PtCl2(PhCN)2 in which polymers were formed as by-products, in the case of 14 three other platinacyles 18 - 20 with a chain-like structure were formed. Trifunctional primary phosphines of the type 1,3,5-[PH2(CH2)n]3C6H3 (26 - 28) were obtained via an Arbusov reaction between the 1,3,5-tris(bromoalkyl)benzenes 3 - 6 and P(OEt)3 followed by a reaction of the trisphosphonates 1,3,5-[(EtO)2P(O)(CH2)n]3C6H3 (21 - 24) with LiAlH4. A straightforward conversion of these sensitive key phosphines 26 - 28 to the corresponding water-soluble ligands 1,3,5-tris-[bis(hydroxymethyl)phosphinylalkyl]benzenes 29 - 31 and 1,3,5-tris[bis(2'-diethylphosphona-toethyl)phophinylalkyl]benzenes 32 - 34 was achieved by formylation with formaldehyde and hydrophosphonation with diethyl vinylphosphonate, respectively. A five component self-assembly consisting of three equivalents of the platinum(II) complex Cl2Pt(NCPh)2 and two equivalents of the ligands 32 - 34 under high dilution conditions resulted in the formation of the nanoscaled, water-soluble triplatinacyclophanes 35 - 37 in high yields.

The structures of the metallacycles 1, 15 - 17 and 35 - 37 as well as 18 - 20 were elucidated by 31P{1H}, 13C{1H}, and 195Pt{1H} NMR spectroscopic investigations.