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)Pt{4,4′-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)Pt{4,4′-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)Pt{4,4′-bpy-N-ⁿBu}][PtCl₃(dmso)] ([trans-2b][PtCl₃(dmso)]).