Crystal structure and photoelectricity property of Fe(II/III) coordination supermolecules

Three new mixed-ligand Fe(II/III) complexes [Fe 2 (μ 2 -btec)(μ 2 -H 2 btec)(phen) 2 (H 2 O) 2 ] n (1), [Fe 2 (btec) (phen) 2 (H 2 O) 4 ] (2), and “[Fe( o -pha)(phen)(H 2 O)]·H 2 O” n (3) (phen=1,10-phenanthroline, o -H 2 pha= o -phthalic acid, H 4 btec=1,2,4,5-benzenetetracarboxylic acid) have been hydrothermally synthesized and detected by single crystal X-ray diffraction, showing that complexes (1) and (2) are both bridged by the betc 4− ligands to form 1D chain and dinuclear structure and complex (3) is bridged by the o -pha groups to form 1D chain structure. The coordinated modes of the carboxyl groups adopt μ 2 -η 1 η 1 ηη 1 η 1 and μ 2 -η 2 η 1 respectively in complexes (2) and (3). The betc groups in complex (1) show two different coordinated modes: μ 2 -η 1 η 1 η 1 η 1 and μ 2 -η 1 η 1 . In addition, the hydrogen bonds and π...π type interactions make the complex molecule further connect to three-dimensional and two-dimensional networks respectively. These complexes are detected by IR, UV-Vis-NIR and surface photovoltage spectrum (SPS). The SPS of complexes (1)–(3) indicate that there are positive SPV responses in the range of 300–600 nm and show p -type semiconductor characteristic. Because the structure, the valence and the coordinative environment of the Fe ions are all different in the three complexes, the intensity, position and the number of the response bands are different obviously. The results of SPS are corresponding with UV-Vis-NIR spectra.