Several dinuclear lanthanide complexes of Ln2(HTH)6TPPHZ (Ln=Eu, Sm, Er, Nd, Yb, Ho; TPPHZ=Tetrapyrido (3,2-a:2',3'-c:3',2"-h:2"',3'"-j) phenazine; HTH=4,5,5,6,6,6-heptafluroro-1-(2-thienyl)hexane-1,3-dione were synthesized and their photoluminescence properties were investigated. After ligand-mediated excitation, all the complexes showed the characteristic luminescence of the corresponding Ln(III) ions in the visible and NIR regions attributed to energy transfer from the ligands to the metal center. For Eu2(HTH)6TPPHZ complex, the quantum efficiency was calculated as 9.6% with the major 5D0 lifetime (477.86 μs) by the equation Φ=τobs/τR, where τobs was observed luminescence lifetime and τR was radiative (or natural) lifetime (5 ms), and 14.9% with air-equilibrated aqueous [Ru(bpy)3](II)·2Cl- solution as a standard sample (Φstd=2.8%), in CH2Cl2 solution at room temperature.
The reactions of 6-phosphononicotinic acid (pnaH3) and metal salts result in three new compounds, namely, M(pnaH)-(H2O)3·H2O [M = Co(Ⅱ) (1), Ni(Ⅱ) (2), Zn(Ⅱ) (3)]. These compounds are isostructural and contain 21 helical chains made up of corner-sharing {MO5N} octahedra and {PO3C} tetrahedra. The chains are further connected by extensive hydrogen bonds to form a three-dimensional supramolecular structure. Magnetic studies reveal that dominant antiferromagnetic interactions are mediated in both 1 and 2. Interestingly the dehydrated compound 1 shows metamagnetic behavior at low temperature.
WANG PengFei, DUAN Yan & ZHENG LiMin State Key Laboratory of Coordination Chemistry
Two cyano-bridged heterobimetallic coordination polymers,[{Mn(dpa)2}2W(CN)8·CH3CN·4H2O]n(1)(dpa = 2,2'-dipyridylamine) and [Mn2(H2O)4{W(CN)8}·3H2O]n(2),have been synthesized and characterized structurally and magnetically.X-ray analysis shows that complex 1 is a one-dimensional(1-D) polymer of W2(CN)4Mn2 square units in which adjacent square fragments are interlinked by sharing [W(CN)8]4-moieties to form an infinite chain.Complex 2 is a three-dimensional(3-D) polymer,which shows an unforeseen structure,exhibiting a 3-D open network with a 1-D channel(ca.13.21 × 11.82 ).Fitting of the magnetic properties indicates that both polymers exhibit weakly antiferromagnetic interactions between the adjacent Mn ions.
LIU BaoLin,XIAO HongPing,SONG You & YOU XiaoZeng State Key Laboratory of Coordination Chemistry,Nanjing National Laboratory of Microstructures,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210093,China
