Irreversible and reversible formation of a [2]rotaxane containing platinum(ii) complex with an N-alkyl bipyridinium ligand as the axis component
作者:Yuji Suzaki、Toshiaki Taira、Kohtaro Osakada
DOI:10.1039/b610087b
日期:——
An N-Alkyl bipyridinium having a polymethylene chain and a bulky aryl group at the end, [4,4′-bpy-N-(CH2)10OC6H3-3,5-tBu2]Cl ([1a]Cl), reacts with K[PtCl3(dmso)] to produce the Pt complex with the N-alkyl bipyridinium ligand [Cl2(dmso)Pt4,4′-bpy-N-(CH2)10OC6H3-3,5-tBu2}][PtCl3(dmso)] as a 6 : 1 mixture of trans and cis isomers ([trans-2a][PtCl3(dmso)] and [cis-2a][PtCl3(dmso)]). Addition of α-cyclodextrin (α-CD) to a solution of [1a]Cl in dmso-d6/D2O (3 : 1) forms [2]pseudorotaxane [4,4′-bpy-N-(CH2)10OC6H3-3,5-tBu2}·(α-CD)]Cl ([3a]Cl) which is equilibrated with [1a]Cl and α-CD in solution. The reaction of K[PtCl3(dmso)] with [3a]Cl affords the [2]rotaxane [trans-Cl2(dmso)Pt4,4′-bpy-N-(CH2)10OC6H3-3,5-tBu2}·(α-CD)][PtCl3(dmso)] ([trans-4a][PtCl3(dmso)]) which contains α-CD and [trans-2a][PtCl3(dmso)] as the cyclic and axis components, respectively. Dissolution of a mixture of [trans-2a][PtCl3(dmso)], [cis-2a][PtCl3(dmso)] and α-CD in dmso-d6/D2O (3 : 1) forms a mixture of the rotaxanes containing [trans-4a-d6][PtCl3(dmso)] and [cis-4a-d6][PtCl3(dmso)]. The reaction involves partial dissociation of the bipyridinium from Pt of [trans-2a][PtCl3(dmso)] or [cis-2a][PtCl3(dmso)] to yield [1a][PtCl3(dmso)] and formation of pseudorotaxane with α-CD, followed by recoordination of the bipyridinium to the Pt. The reversible formation of the Pt–N coordination bond is studied in a dmso solution of the N-butyl compounds [trans-Cl2(dmso)Pt4,4′-bpy-N-nBu}][PtCl3(dmso)] ([trans-2b][PtCl3(dmso)]).
一种具有聚亚甲基链和末端庞大芳基的N-烷基联吡啶盐,[4,4'-联吡啶-N-(CH\(}_2}\))\(}_10}\)OC\(}_6}\)H\(}_3}\)-3,5-二叔丁基]Cl ([1a]Cl),与K[PtCl\(}_3}\)(dmso)]反应生成具有N-烷基联吡啶盐配体的Pt复合物,即[Cl\(}_2}\)(dmso)Pt4,4'-联吡啶-N-(CH\(}_2}\))\(}_10}\)OC\(}_6}\)H\(}_3}\)-3,5-二叔丁基}][PtCl\(}_3}\)(dmso)]作为反式和顺式异构体的6:1混合物([trans-2a][PtCl\(}_3}\)(dmso)]和[cis-2a][PtCl\(}_3}\)(dmso)]).将α-环糊精(α-CD)加入到dmso-d\(}_6}\)/D\(}_2}\)O(3:1)中的[1a]Cl溶液中,生成[2]伪轮烷[4,4'-联吡啶-N-(CH\(}_2}\))\(}_10}\)OC\(}_6}\)H\(}_3}\)-3,5-二叔丁基}·(α-CD)]Cl ([3a]Cl),其在溶液中与[1a]Cl和α-CD处于平衡状态.K[PtCl\(}_3}\)(dmso)]与[3a]Cl反应得到[2]轮烷[trans-Cl\(}_2}\)(dmso)Pt4,4'-联吡啶-N-(CH\(}_2}\))\(}_10}\)OC\(}_6}\)H\(}_3}\)-3,5-二叔丁基}·(α-CD)][PtCl\(}_3}\)(dmso)]([trans-4a][PtCl\(}_3}\)(dmso)]),其中α-CD和[trans-2a][PtCl\(}_3}\)(dmso)]分别为环状和轴向组分.将[trans-2a][PtCl\(}_3}\)(dmso)]、[cis-2a][PtCl\(}_3}\)(dmso)]和α-CD的混合物溶解在dmso-d\(}_6}\)/D\(}_2}\)O (3:1)中,形成含有[trans-4a-d\(}_6}\)][PtCl\(}_3}\)(dmso)]和[cis-4a-d\(}_6}\)][PtCl\(}_3}\)(dmso)]的轮烷混合物.该反应涉及从[trans-2a][PtCl\(}_3}\)(dmso)]或[cis-2a][PtCl\(}_3}\)(dmso)]中的Pt部分解离联吡啶盐,生成[1a][PtCl\(}_3}\)(dmso)]并与α-CD形成伪轮烷,随后联吡啶盐重新配位到Pt.Pt-N配位键的可逆形成在N-丁基化合物[trans-Cl\(}_2}\)(dmso)Pt4,4'-联吡啶-N-nBu}][PtCl\(}_3}\)(dmso)]([trans-2b][PtCl\(}_3}\)(dmso)])的dmso溶液中进行了研究.