Coordination Cluster Analogues of the High‐Spin [Mn19] System with Functionalized 2,6‐Bis(hydroxymethyl)phenol Ligands

A series of 2,6-bis(hydroxymethyl)-4-R-phenol ligands (H3LR; R = H, F, Cl, Br, I, Ph, NH2, NO2, SMe) have either been newly synthesized or the existing syntheses have been significantly improved to investigate ligand-functionalized analogues of the previously published coordination cluster [MnIII12MnII7(μ4-O)8(μ3-N3)8(HLMe)12(MeCN)6]Cl2·10MeOH·MeCN (1) with S = 83/2. The crystal structures and magnetic properties of three such Mn19 clusters, namely, [MnIII12MnII7(μ4-O)8(HLH)12(μ3-Cl)7(μ3-OMe)(MeOH)6]Cl2·16H2O·10MeOH·MeCN (3), [MnIII12MnII7(μ4-O)8(HLI)12(μ3-N3)8(MeOH)6](O2CH)2·16MeOH·10MeCN (4) and [MnIII12MnII7(μ4-O)8(μ3-Cl)7.7(μ3-OMe)0.3(HLSMe)12(MeOH)6]Cl2·27MeOH (5) are reported and compared to those of the parent cluster. When these ligands are functionalized with substituents of moderate electronegativity, it is possible to synthesize Mn19 analogues; however, when such ligands bear highly electron-donating (amino) or -withdrawing (nitro) substituents, the Mn19 analogues are no longer accessible. The Mn19 cluster framework is both magnetically and structurally robust with respect to the electron-donor/acceptor characteristics of the ligand substituent; therefore, the Mn19 system is an excellent platform for peripheral chemical engineering.