Anion-Dependent Assembly of Four Sensitized Near-Infrared Luminescent Heteronuclear ZnII–YbIII Schiff Base Complexes from a Trinuclear ZnII Complex

New Coordination Compounds of CuII with Schiff Base Ligands—Crystal Structure, Thermal, and Spectral Investigations

The new mono-, di- and tetranuclear coordination compounds [Cu(HL1)]·H2O (1), [Cu2(L1)(OAc)(MeOH)]·2H2O·MeOH (2), [Cu4(L2)2(OAc)2]·4MeOH (3), and [Cu4(L2)2(OAc)2]·4H2O·4MeOH (4) were synthesized by the direct reaction of 2,2′-{(2-hydroxypropane-1,3-diyl)bis[nitrilomethylidene]}bis(4-bromo-6-methoxyphenol) (H3L1) or 2,2′-{(2-hydroxypropane-1,3-diyl)bis(nitriloeth-1-yl-1-ylidene)}diphenol (H3L2) and the Cu(II) salt. They were characterized by elemental analysis, X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, simultaneous thermal analysis and differential scanning calorimetry (TG/DSC), and thermal analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR) techniques and the single crystal X-ray diffraction study. In the dinuclear complex 2, the copper(II) ions are bridged by an alkoxo- and a carboxylato bridges. The tetranuclear complexes 3 and 4 are formed from dinuclear species linkage through the phenoxo oxygen atoms of the fully deprotonated H3L2. Compounds 1–4 are stable at room temperature. During heating in air, at first, the solvent molecules (water and/or methanol) are lost and after that, the organic part undergoes defragmentation and combustion. The final decomposition solid product is CuO. The main gaseous products resulting from the thermal degradation of 1–4 in a nitrogen atmosphere were: H2O, MeOH, CH3COOH, CH4, C6H5OH, CO2, CO, and NH3.

Co-crystal structure of a dinuclear (Zn-Y) and a trinuclear (Zn-Y-Zn) complexes derived from a Schiff base ligand

The present investigation describes the synthesis and structural study of a metal-zinc ligand [ZnL.H2O], which was used to generate three dimensional supramolecular complex formulated as [Y{Zn(L)(SCN)}(SCN)2].[Y{Zn(L)(SCN)}2(DMF)2].(NO3). The title compound crystallizes in the triclinic space group P-1 with the following unit cell parameters: a = 14.8987(7) Å, b = 15.6725(8) Å, c = 19.2339(10) Å, a = 94.610(4)°, β = 103.857(4)°, γ = 101.473(4)°, V = 4234.4(4) Å3, Z = 2, R1 = 0.063 and wR2 = 0.96. For this compound, the structure reveals that one heterodinuclear unit [Y{Zn(L)(SCN)}(SCN)2] is co-crystallized with a heterotrinuclear unit [Y{Zn(L)(SCN)}2(DMF)2].(NO3). In the dinuclear moiety, the organic molecule acts as a hexadentate ligand and in the trinuclear unit, it acts as a pentadentate ligand with one of the oxygen methoxy group remaining uncoordinated. In both units the coordination environment of the zinc metal can be described as distorted square pyramidal. In the dinuclear unit the Y(III) is hexacoordinated while it is octacoordinated in the trinuclear unit. The environment of the Y(III) can be described as a distorted octahedral geometry in the dinuclear and as a distorted square antiprism in the trinuclear units respectively.

Anion-dependent thermo-responsive supramolecular superstructures of Cu(ii) macrocycles

A heteroditopic ligand predominantly self-assembled into a dinuclear Cu(ii) macrocycle with various Cu²⁺ salts. However, each macrocycle is further hierarchically assembled to distinct supramolecular superstructures, where the shape of the morphology is found to be highly dependent on the counter-anions and temperature.

Different conjugated system Zn(ii) Schiff base complexes: supramolecular structure, luminescent properties, and applications in the PMMA-doped hybrid materials

Five Zn(ii) complexes with different conjugated systems were synthesized. Zn3 was incorporated into PMMA, creating a high performance material.

Syntheses, structures, luminescence and magnetic properties of three high-nuclearity neodymium compounds based on mixed sulfonylcalix[4]arene-phosphonate ligands

The solvothermal reactions of p-tert-butylsulfonylcalix[4]arene (H₄BSC4A), phosphonic acid and neodymium chloride have resulted in three novel high-nuclearity neodymium coordination compounds.

Two samarium(iii) complexes with tunable fluorescence from in situ reactions of 2-ethoxy-6-((pyridin-2-ylmethylimino)methyl)phenol with Sm3+ ion

The solvothermal in situ C–C coupling reaction promoted by Sm³⁺ ion in Schiff base –CHN–CH₂– system is firstly reported, and two resulting temperature-dependent Sm(iii)-complexes 1 and 2 have different luminescent performance.

Cation-Exchange Porosity Tuning in a Dynamic 4d-4f-3d Framework for Ni(II) Ion-Selective Luminescent Probe

A heterometallic complex {[Yb2(L)6Cd2][Cd(H2O)6]·6H2O}n (Yb-Cd) (H2L = oxidiacetic acid) was synthesized under hydrothermal conditions. In Yb-Cd, each L chelates to one Yb(3+) center and bonds to two Cd(2+) ions in an anti-anti configuration. Yb and Cd atoms are arrayed alternatively and connected by O-C-O bridges to form a cubic octahedral cage as the secondary building unit. Consequently, topological NaCl nets with high symmetry in the cubic space group Fd-3c have been constructed. The [Cd(H2O)6](2+) moieties lying in the porosity of anionic metal-organic framework (MOF) act as the thermodynamically stable species, required to balance the two negative charges of [Yb2(L)6Cd2](2-) in Yb-Cd. Interestingly, when Yb-Cd was employed as a precursor and emerged in the aqueous solution of Mn(ClO4)2·6H2O or Zn(ClO4)2·6H2O, a reversible single-crystal-to-single-crystal transformation process driven by [Cd(H2O)6](2+) cations has been exhibited to generate the heterotrimetallic coordination polymer {[Yb2(L)6Cd2][Mn(H2O)6]·6H2O}n (Yb-Cd-Mn) or {[Yb2(L)6Cd2][Zn(H2O)6]·6H2O}n (Yb-Cd-Zn). To the best of out knowledge, Yb-Cd-Mn and Yb-Cd-Zn are the first examples representing 4d-4f-3d polymers based on multicarboxylic acid. Luminescent studies reveal that Yb-Cd-Zn may serve as a good candidate of Ni(2+) a luminescent probe. To our knowledge, Yb-Cd-Zn represent the fist example of the 4d-4f-3d framework to exhibit luminescent selectivity for Ni(2+).

Two Schiff base ligands for distinguishing ZnII/CdII sensing—effect of substituent on fluorescent sensing

Two Schiff base ligands (HL1, HL2) were synthesized as fluorescent sensors for Zn²⁺ or Cd²⁺. With an ethoxyl group, HL1 can distinguishingly sense Zn²⁺ and Cd²⁺, while HL2 exclusively responds to Zn²⁺.

Anion-dependent assembly of Dy complexes: structures and magnetic behaviors

The in situ reaction of 2-aldehyde-8-hydroxyquinoline, histamine and LnX₃·6H₂O (X⁻ = OAc⁻, NO₃⁻ and ClO₄⁻) affords three distinct species of eight lanthanide complexes.

Structure variations of a series of lanthanide complexes constructed from quinoline carboxylate ligands: photoluminescent properties and PMMA matrix doping

A series of lanthanide complexes constructed from H₂qldc are synthesized and the luminescence properties discussed.

First tetrazole-bridged d–f heterometallic MOFs with a large magnetic entropy change

The first example of tetrazole-bridged 3d–4f heterometallic MOFs {(H₃O)₃[Gd₃Mn₂(Trz)₄]·12H₂O}_n was obtained, exhibiting a large magnetic entropy change.