Three cyanide-bridged dodecanuclear macrocyclic wheel-like complexes [Cr(bpmb)(CN)2]6[Mn(5-Brsalpn)]6-12H2O (1), [Co(bpmb)(CN)2]6[Mn(5-Brsalpn)]6-12H2O (2) and [Co(bpmb)(CN)2]6[Mn(5-Clsalpn)]6-24H2O-8CH3CN (3) [bpmb2- = 1,2-bis(pyridine-2-carboxamido)-4-methylbenzenate dianion; 5-Brsalpn2-= N,N’-propylenebis(5-bromosalicylideneaminato) dianion; 5-Clsalpn2-= N,N’-propylenebis(5-chlorosalicylideneaminato) dianion] have been synthesized and their crystal structures and magnetic properties have been investigated. The three compounds are structurally isomorphous and consist of alternating Mn( Ⅲ )-Schiff base cations and [M(bpmb)(CN)2]- anions, generating cyanide-bridged nanosized dodecanuclear macrocyclic structures with an approximate diameter of 2 nm. The study of the magnetic properties of complex 1 reveals an antiferromagnetic interaction between the Cr(Ⅲ) and Mn(Ⅲ) ions through the cyanide bridges. A best-fit to the magnetic susceptibility of the complex leads to a magnetic coupling constant of JCrMn = -2.65(6) cm-1 on the basis of a one-dimensional alternating chain model with the Hamiltonian H =-JCrMn∑N to 1=0 Si·Si+1. Three cyanide-bridged dodecanuclear macrocyclic wheel-like complexes [Cr (bpmb) (CN) 2] 6 [Mn (5-Brsalpn)] 6-12H2O (1) 5-Brsalpn] 6-12H2O (2) and [Co (bpmb) (CN) 2] 6 [Mn (5-Clsalpn)] 6-24H2O-8CH3CN 2-carboxamido) -4-methylbenzenate dianion; 5-Brsalpn2- = N, N’-propylenebis (5-bromosalicylideneaminato) dianion; 5-Clsalpn2- = N, and their crystal structures and magnetic properties have been investigated. The three compounds are structurally isomorphous and consist of alternating Mn (III) -Schiff base cations and [M (bpmb) (CN) 2] -anions, generating cyanide- bridged nanosized dodecanuclear macrocyclic structures with an approximate diameter of 2 nm. The study of the magnetic properties of complex 1 reveals an antiferromagnetic interaction between the Cr (III) and Mn (III) ions through the cyanide bridges. A best-fit to the magnetic susceptibility of the complex leads to a magnetic c oupling constant of JCrMn = -2.65 (6) cm -1 on the basis of a one-dimensional alternating chain model with the Hamiltonian H = -JCrMnΣN to 1 = 0 Si · Si + 1.