The C–F…F–C short contacts in the metal complexes of fluoro-phenyl-acrylic acids

Four new complexes of fluoro-phenyl-acrylic acids (E)-3-(3-fluoro-phenyl)-acrylic acid (L1) [Mn3(L1)6(L2)2]·H2O·CH3CN (1), [Zn2(L1)4(L3)]n (2), [Mn(L1)2(H2O)2]n (3) and [Co(L1)2(H2O)2]n (4) (L2=1,10-phenanthroline, L3=4,4′-bipy) have been synthesized based on the molecular design and research of halogen–halogen interactions (especially fluoro–fluoro contact). The structure analyses reveal that complex 1 is a trinuclear complex, which is blocked by L2. Complex 2 is a 1D chain bridged through L3. Complexes 3 and 4 exhibit 2D grid like metal–organic framework structures through carboxylato bridge ligand. Variable-temperature magnetic measurements showed an antiferromagnetic interaction between Mn(II) ions and between Co(II) ions in complexes 3 and 4, respectively. A short C−F…F−C contact with a distance of 2.953 Å was found between the trinuclear coordination compound 1.

Graphical AbstractThe short distance between F…F (2.953 Å) was found in the complex of [Mn3(L1)6(L2)2]·H2O·CH3CN (L1=(E)-3-(3–fluoro-phenyl)-acrylic acid, L2=1,–10–phenanthroline).Figure optionsDownload as PowerPoint slideResearch highlights
► Four new complexes of fluoro-phenyl-acrylic acids (E)-3-(3-fluoro-phenyl)-acrylic acid (L1) [Mn3(L1)6(L2)2]·H2O·CH3CN (1), [Zn2(L1)4(L3)]n (2), [Mn(L1)2(H2O)2]n (3) and [Co(L1)2(H2O)2]n (4) (L2=1,10-phenanthroline, L3=4,4′-bipy) have been synthesized based on the molecular design and research of halogen–halogen interactions (especially fluoro–fluoro contact).
► A short C−F…F−C contact with a distance of 2.953 Å was found between the trinuclear coordination compound 1.
► Variable-temperature magnetic measurements showed an antiferromagnetic interaction between Mn(II) ions and between Co(II) ions in complexes 3 and 4, respectively.