1.Synthesis, crystal structure, photoluminescence property and photoelectronic behavior of two uranyl-organic frameworks constructed from 1, 2, 4, 5-benzenetetracarboxylic acid as ligand.
Hou YN1, Xing YH2, Bai FY3, Guan QL1, Wang X1, Zhang R1, Shi Z4. Spectrochim Acta A Mol Biomol Spectrosc. 2014 Apr 5;123:267-72. doi: 10.1016/j.saa.2013.12.036. Epub 2013 Dec 19.
By using 1, 2, 4, 5-benzenetetracarboxylic acid as organic ligands, two uranyl coordination complexes, (UO2)2(bta)(DMA)2 (1) and [(UO2)2(bta)(μ3-OH2)]·2[HN(CH3)2]·H2O (2) (H4bta=1, 2, 4, 5-benzenetetracarboxylic acid, DMA=N,N-Dimethylacetamide) were synthesized. The X-ray single crystal analysis revealed that complex 1 exhibits a 3-demensional framework, while complex 2 exhibits a 2-demensional framework. In order to furthermore characterize the two complexes and extend their functional properties, spectroscopies of IR, UV-vis, photoluminescence and surface photovoltage were also studied primarily. In addition, thermogravimetric analyses and photocatalytic studies for complexes 1 and 2 were discussed in detail.
2.Neutron diffraction studies of the molecular compound [Co2(bta)]n (H4bta =1,2,4,5-benzenetetracarboxylic acid): in the quest of canted ferromagnetism.
Fabelo O1, Cañadillas-Delgado L, Pasán J, Díaz-Gallifa P, Ruiz-Pérez C, Lloret F, Julve M, Puente Orench I, Campo J, Rodríguez-Carvajal J. Inorg Chem. 2013 Nov 4;52(21):12818-27. doi: 10.1021/ic402186p. Epub 2013 Oct 16.
The exchange mechanism and magnetic structure of the organic-inorganic layered molecule-based magnet [Co2(bta)]n (1) (H4bta =1,2,4,5-benzenetetracarboxylic acid) have been investigated through variable-temperature magnetic susceptibility measurements and supported with a series of neutron diffraction experiments. Cryomagnetic studies have shown an antiferromagnetic ordering at a transition temperature of 16 K that is followed by the appearance of a weak ferromagnetism below 11 K. The weak antiferromagnetic interlayer interaction plays an important role in this system in spite of the long interlayer separation. A ferromagnetic ordering is induced by applied magnetic fields greater than 1800 G (metamagnetic behavior), and a slow magnetic relaxation from this ferromagnetic phase to the antiferromagnetic one is observed. The magnetic structure of 1 has been elucidated at low temperatures in zero field by neutron powder diffraction measurements and was found to be of antiferromagnetic nature with the local cobalt(II) spins (magnetic moments) being aligned ferromagnetically in the ac plane and antiferromagnetically coupled along the crystallographic b axis.
3.A series of MOFs based on a triangular tri(4-pyridylphenyl)amine ligand combined with carboxylate or nitrate auxiliary ligands.
Meng F1, Zhang M, Shen K, Li Y, Zheng H. Dalton Trans. 2015 Jan 21;44(3):1412-9. doi: 10.1039/c4dt02811b.
A series of new metal-organic frameworks (MOFs) based on a triangular tri(4-pyridylphenyl)amine (TPPA) ligand that possess novel structures and features, namely [Co2(TPPA)2(1,3-bdc)2(H2O)]n (); [Zn(TPPA)(1,3-bdc)]n (); [Zn6(TPPA)2(betc)(Hbetc)2(H2betc)(H2O)6·7H2O·2DMA]n () and [Cu(TPPA)(NO3)2(H2O)]·2H2O]n () (1,3-H2bdc = 1,3-benzenedicarboxylic acid, betc = 1,2,4,5-benzenetetracarboxylic dianhydride), have been synthesized under solvothermal conditions. In our work different MOFs were synthesized from different metal ions and in different solvents, leading to a variety of coordination modes and structures. In addition, the photochemical properties of compounds and the ligands in the solid state were studied.
4.Enhanced emission of ultra-small-sized LaF3:RE3+ (RE = Eu, Tb) nanoparticles through 1,2,4,5-benzenetetracarboxylic acid sensitization.
Li S1, Zhang X, Hou Z, Cheng Z, Ma P, Lin J. Nanoscale. 2012 Sep 21;4(18):5619-26. doi: 10.1039/c2nr31206a. Epub 2012 Aug 3.
Uniform, ultra-small-sized and well-water-dispersible LaF(3) nanoparticles doped with trivalent rare earth (RE) ions (Eu(3+) or Tb(3+)) have been synthesized by a simple, low temperature synthesis route. The nanoparticles, with sizes of about 3.2 nm (for those doped with Eu(3+)) and 3.0 nm (for those doped with Tb(3+)), are roughly spherical and monodisperse. 1,2,4,5-Benzenetetracarboxylic acid (labeled as BA) as sensitizer has been bonded to the surface of the nanoparticles, which can sensitize the emission of RE(3+) in the LaF(3) nanoparticles. The BA-LaF(3):RE(3+) (RE = Eu or Tb) nanoparticles have a broad absorption band in the UV domain, and show enhanced luminescence of RE(3+) based on an energy transfer from BA ligands to RE(3+) ions (i.e. the so-called "antenna effect"). Due to the dual protection of organic ligands (BA) and inorganic matrices (LaF(3)), BA-LaF(3):RE(3+) (RE = Eu or Tb) nanoparticles have longer excited state lifetimes than LaF(3):RE(3+) (RE = Eu or Tb) nanoparticles as well as lanthanide coordination polymers of BA.