Network-Selectivity, Magnetism, and Proton Conduction of 2-D and 3-D Metal-Organic Frameworks of the Constituents {P(CH2OH)4}+/MII (MnII, FeII, or CoII)/[CrIII(ox)3]3.

Two types of metal-organic frameworks (MOFs), including {P(CH2OH)4}6[MnII3{CrIII(ox)3}4]·10H2O·2EtOH (1) and {P(CH2OH)4}[MIICrIII(ox)3]·H2O (M = Fe (2), and Co (3)), are selectively formed by a reaction of {P(CH2OH)4}Br, MCl2, and (NH4)3[Cr(ox)3]. 1 has the 3-D anionic framework, [Mn3{Cr(ox)3}4]n6n-, consisting of the Mn4Cr4 octagonal and Mn6Cr6 dodecagonal channels, in which {P(CH2OH)4}+ ions and the solvation molecules (H2O and EtOH) are accommodated. 2 and 3 have a 2-D network of oxalate-bridged bimetallic sheets with an intercalation of {P(CH2OH)4}+ ions. Magnetic studies revealed ferromagnetic ordering in all the MOFs, with TC = 5.6 K for 1, 10.6 K for 2, and 12.2 K for 3. The {P(CH2OH)4}+ ions in the MOFs promote proton transfer via the vehicle mechanism, which gives rise to a significant room-temperature conductivity of 1.03 × 10-4 S cm-1 at 70% RH for 1, 4.60 × 10-6 S cm-1 at 60% RH for 2, and 3.04 × 10-5 S cm-1 at 70% RH for 3.