Cobalt(II) complexes with pentadentate Schiff bases 2,6-diacetylpyridine hydrazones: Syntheses and structures

Seven new cobalt(II) complexes based on the Schiff bases, 2,6-diacetylpyridine bis(isonicotinoylhydrazone) (H₂L¹) and 2,6-diacetylpyridine bis(nicotinoylhydrazone) (H₂L²), are synthesized and studied by X-ray diffraction analysis: [Co(H₂L¹)(NCS)₂] · 2.25H₂O (I), [Co(H₂L²)(NCS)₂] · CH₃OH (II), [Co(H₂L²)(NCS)(H₂O)]NCS (III), [Co(H₄L¹)(NCS)₂](NO₃)₂ · 2H₂O (IV), [Co(H₄L¹)(NCS)₂][Co(NCS)₄] · 0.75H₂O (V), [Co(H₄L²)(NCS)₂][Co(NCS)₄] · 1.75H₂O (VI), and [Co(H₂L²)(NCS)(CH₃OH)]₂[Co(NCS)₄] · 2CH₃OH (VII) (CIF files CCDC 941186 (I), 1457906 (Ia), 1457905 (II), 941187 (III), 1457907 (IV), 1457908 (V), 1457909 (VI), and 941188 (VII)). The organic ligands in the complexes act as pentadentate neutral H₂L or doubly protonated (H₄L)²⁺ coordinated through the same set of donor atoms N₃O₂. In all compounds I–VII, the coordination polyhedron of the Co²⁺ ion in a complex with the Schiff bases has a shape of a pentagonal bipyramid. The hydrazones are arranged in the equatorial plane of the bipyramid. Its axial vertices are occupied by the nitrogen atoms of the NCS￣ anions in compounds I, II, and IV–VI and by the nitrogen atoms of NCS￣ and oxygen of the water molecule in compound III or methanol in compound VII. The NO ₃ ^- anions or [Co(NCS)₄]^2￣ complex anions obtained by the reactions are involved along with the NCS￣ anions in the formation of compounds IV–VII.     

Synthesis and structure of tris(4-<Emphasis Type="Italic">N,N</Emphasis>-dimethylaminophenyl) antimony(V) dicarboxylates and diaroxides

Tris(4-N,N-dimethylaminophenyl)antimony dicarboxylates (4-Me₂NC₆H₄)₃Sb[OC(O)R]₂ (R = C₆H₄Me-2 (I), C₆H₄Me-4 (II), CH=CHPh (III)), (4-Me₂NC₆H₄)₃Sb[OC(O)C(O)O] (IV), and (4-Me₂NC₆H₄)₃Sb[OC(O)C₆Cl₄C(O)O] (V)) and tris(4-N,N-dimethylaminophenyl)antimony diaroxides (4-Me₂NC₆H₄)₃Sb(OAr)₂ (Ar = Ph (VI), C₆H₂Br₃-2,4,6 (VII), and C₆H₃Me₂-2,6 (VIII)) have been synthesized by the reaction of tris(4-N,N-dimethylaminophenyl)antimony in ether with carboxylic acids or phenols in the presence of hydrogen peroxide. According to X-ray diffraction analysis data, the Sb atoms in compounds I and VII have a distorted trigonal-bipyramidal coordination, and the axial OSbO angles are 175.4(1)° and 177.9(3)°, respectively. The Sb-O bond lengths are 2.133(3) and 2.142(2) Å in compound I and 2.089(5) Å in compound VII.     

Tetraphenylphosphonium carboxylates and sulfonates. Synthesis and structure

The reaction of the pentaphenyphosphorus solvate Ph₅P·1/2PhH (I) with carboxylic and sulfonic acids was used to synthesize tetraphenylphosphonium carboxylates Ph₄POC(O)R, R = C₆H₄(2-OH) (II), C₆H₄ (2-COOH) (III), H (IV), Me (V), CCl₃ (VI), Ph (VII), PhCH=CH (VIII), CH₂CH₂C(O)OH (IX), CH=CHC(O) OH(X), and CH₂C(O)OH (XI) and tetraphenylphosphonium sulfonates Ph₄POSO₂Ar, Ar = Ph (XII), C₆H₄Me₄ (XIII), and C₆H₃(-COOH)(4-OH) (XIV). Compound XII was also prepared from compound I and SO₃ in benzene. According to X-ray diffraction data, the crystals of I contain two types of crystallographically independent molecules with a slightly distorted trigonal-bipyramidal configuration [Ia, CaxPCax 178.44(8)°, P- C_ax 1.985(2), 1.987(2) Å, P-C_eq 1.854(2), 1.846(2), 1.840(2) Å; Ib, C_axPC_ax 178.45(9)°, P-C_ax 1.980(2), 1.975 (2) Å, P-C_eq 1.840(2), 1.846(2), 1.854(2) Å]. In the cations of compounds II, III and XIV, the coordination of the phosphorus atom is tetrahedral [CPC angle: II, 106.2(2)?111.6(1)°; III, 104.01(6)?113.03(6)°; XIV, 107.54 (6)?112.79(6)°]; the anions contain intramolecular O-H?O hydrogen bonds between the hydroxyl hydrogen atom and carboxyl oxygen atom (II, 1.34; III, 1.23; and XIV, 1.83 Å).     

Tetra- and triarylantimony pentafluoroand pentachlorophenoxides: Synthesis and structure

2,3,4,5,6-Pentafluorophenoxytetraphenylantimony (I), 2,3,4,5,6-pentachlorophenoxytetraphenylantimony (_II), 2,3,4,5,6-pentafluorophenoxytetra-p-tolylantimony (III), and 2,3,4,5,6-pentachlorophenoxytetra-p-tolylantimony (IV) were synthesized by the reaction of pentaarylantimony (Ar = Ph, p-Tol) with pentafluoro- and pentachlorophenol in toluene. Compounds I–IV were also synthesized with yields of up to 95% from pentaarylantimony and triarylantimony diaroxides. Triarylantimony diaroxides Ph₃Sb(OC₆F₅)₂ (V), Ph₃Sb(OC₆Cl₅)₂ (VI), p-Tol₃Sb(OC₆F₅)₂ (VII), p-Tol₃Sb(OC₆Cl₅)₂ (VIII) were synthesized from triarylantimony, tert-butylhydroperoxide, and phenol in ether. The Sb atoms in compounds I–VIII had a distorted trigonal bipyramidal coordination with electronegative ligands in axial positions.     

Synthesis and characterization of heteronuclear germanium(IV) lanthanide 1,3-diamino-2-propanoltetraacetates: Crystal and molecular structure of the [Ge(OH)(μ-Hpdta)(μ-OH) Ln(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>] · 2H<Subscript>2</Subscript>O complexes (Ln = Tb,Yb)

In the course of systematic studies, heteronuclear germanium lanthanide complexes based on 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) have been synthesized (Ln = Pr (I), Nd (II, the structure was described in [1]), Sm (III), Eu (IV), Gd (V), Tb (VI), Dy (VII), Ho (VIII), Er (IX), Tm (X), Yb (XI), Lu (XII)). Comparative analysis of their structure as a function of the lanthanide ion has been performed. The analysis is based on a combination of physicochemical data on complexes I–XII, including X-ray crystallographic data for two heteronuclear [Ge(OH)(μ-Hpdta)(μ-OH)Ln(H₂O)₃] · 2H₂O complexes (Ln = Tb (VI) and Yb (XI). Isostructural crystals of VI and XI are monoclinic, Z = 4, space group P2₁/n, a = 9.340(4) and 9.3133(10) Å, b = 10.4839(14) and 10.4561(10) Å, c = 20.246(2) and 20.1222(10) Å, β = 95.12(3)° and 95.275(10)°, V = 1974.5(10) and 1951.2(3) A³, R1 = 0.0277 and 0.0241 for 4527 and 4751 reflections with I > 2σ(I). Crystals of VI and XI are composed of binuclear [Ge(OH)(μ-Hpdta)(μ-OH)Ln(H₂O)₃] molecules and crystal water molecules. The Ge and Ln atoms in VI and XI are linked by the bridging oxygen atom of the hydroxo group (Ge-O, 1.806(2) and 1.812(2) Å; Ln-O, 2.445(3) and 2.405(2) Å, respectively) and by the deprotonated oxygen atom of the isopropanol group of the Hpdta5-ligand (Ge-O, 1.865(2) and 1.864(2) Å; Ln-O, 2.302(2) and 2.255(2) Å in VI and XI, respectively). The coordination sphere of each of the Ge and Ln atoms involves one nitrogen atom (Ge-N, 2.097(3) and 2.096(3) Å; Ln-N, 2.670(3) and 2.628(3) Å in VI and XI, respectively) and two carboxyl oxygen atoms of four acetate arms of the completely deprotonated heptadentate Hpdta^5? ligand (av. Ge-O, 1.922(3) and 1.920(3) Å; Ln-O, 2.349(2) and 2.298(2) Å in VI and XI, respectively). The coordination polyhedron of the Ge atom is completed to a distorted octahedron by the oxygen atom of the terminal hydroxo group (Ge-O, 1.811(2) Å in VI and 1.810(2) Å in XI), and the coordination polyhedron of the Ln atom is completed to an eight-vertex polyhedron by the oxygen atoms of three water molecules (av. Ln-O, 2.378(3) Å in VI and 2.342(3) Å in XI). In the crystals of VI and XI, complex molecules and crystal water molecules are combined by a system of hydrogen bonds into a three-dimensional framework.     

Lanthanide complexes with the Schiff base containing sterically hindered phenol: Synthesis,structure, and luminescence properties

The syntheses of the 2,6-di-tert-butyl-4-(2-hydroxybenzylideneamino)phenolate (L) complexes of Gd (I), Nd (II), Er (III), Yb (IV), Tm (V), Sm (VI), and Tb (VII) are described. The structures of the Gd and Er complexes are determined by X-ray diffraction analysis (CIF files CCDC nos. 1558820 (I) and 1558819 (III)). All synthesized compounds exhibit ligand-centered photoluminescence in a range of 405–485 nm. In addition, the luminescence spectra of solid samples of the neodymium and ytterbium complexes contain narrow bands of f–f transitions characteristic of Nd³⁺ and Yb³⁺ ions.     

Syntheses,crystal structures,and properties of various one- dimensional coordination polymers based on macrocyclic metallic tectons and dicarboxylic acid ligand

The reaction of different macrocyclic metallic tectons and dicarboxylic acid ligand yielded six new coordination polymers, namely, {[(NiL¹)(4,4'-Bpdc)] ? DMF ? 2.5H₂O} _n (I), {[(NiL²)(4,4'-Bpdc)] ? DMF ? 2.5H₂O} _n (II), [(NiL³)₂(4,4'-Bpdc)_1.5][(NiL³)(4,4'-Bpdc)] ? ClO₄ ? 28H₂O (III), {[(NiL⁴)(4,4'-Bpdc)] ? 4H₂O} _n (IV), {[(NiL⁵)(4,4'-Tpdc)] ? 5H₂O} _n (V), {[(NiL³)(4,4'-Tpdc)]} _n (VI) (L¹ = 1,4,7,9,12,14-hexaaza-tricyclo[12.2.1.1^4.7]octadecane, L² = 1,3,10,12,15,18-hexaazatetracyclo[16.2.1.1^12.15.0^4.9]docosane, L³ = 11-methyl-1,4,8,10,13,15-hexaaza-tricyclo[13.3.1.1^4.8]icosane, L⁴ = 1,3,10,12,16,19-hexaazate-tracyclo[17.3.1.1.^12.16,0^4.9]tetracosane, L⁵ = 1,4,8,10,13,15-hexaaza-tricyclo[13.3.1.1^4.8]icosane, 4,4'-Bpdc = 4,4'-biphenyldicarboxylic acid and 4,4'-Tpdc = 4,4'-terphenyldicarboxylic acid) (CIF files CCDC nos. 1055545–1055550 for I–VI, respectively). Except for the different conformations of the macrocyclic metallic tectons or dicarboxylic acid ligands, complexes I–VI crystallized under the same environment, however, they exhibit diverse packing mode of infinite 1D coordination polymers, showing macrocyle or dicarboxylic acid ligand regulated self-assemble. The solid states UV-Vis for complexes I–VI also have been investigated.     

Thermolysis of polynuclear platinum(II) acetamidato complexes

The thermolysis of five polynuclear Pt(II) acetamidato complexes with known structures (I-V) and platinum blue of the composition Pt(NHCOCH₃)₂ · H₂O prepared by two different procedures (VI and VIa) has been studied by differential scanning calorimetry and thermogravimetry. The results of studying the thermolysis of these complexes allows one to assume that the structures of VI and VIa are different: complex VI is polynuclear and consists of binuclear fragments[(H₂O)(NHCOCH₃)Pt(μ-NHCOCH₃)₂Pt(NHCOCH₃)(H₂O)], whereas complex VIa is built of fragments [(H₂O)(NHCOCH₃)Pt(μ-OH)(μ-OH)(μ-NHCOCH₃)Pt(NHCOCH₃)₂].     

Synthesis and molecular structures of tris(thio- and selenophenyl)stannyl complexes of cyclopentadienylcarbonylnitrosylmanganese and their reaction products with tungsten carbony

Reactions of CpMn(CO)(NO)SnCl₃ (I) with sodium benzenethiolate and sodium benzenesele-nolate gave orange crystals of the complexes CpMn(CO)(NO)Sn(EPh)₃, where E = S (II) or Se (III). Treatment of complex II with photochemically generated W(CO)₅(THF) yielded the adduct CpMn(CO)(NO)Sn(SPh)₃ · W(CO)₅ (IV). A similar treatment of complex III resulted in the formation of the ditungsten complex W₂(CO)₄(SePh)₆ (V) with transfer of all chalcogenate groups from tin to tungsten. In reactions of complexes II and III with a Pt₀ complex with phosphine and acetylene, (PPh₃)₂Pt(Ph₂C₂), the chalcogenate groups are transferred from tin. Only the known Pt(II) complexes (PPh₃)₂Pt(EPh)₂), where E= S (VI) or Se (VII). Molecular structures IV and V were characterized by X-ray diffraction. It has been found that the Mn-Sn bond in complex IV (2.5479(9) Å) is nearly the same length as that found earlier for complex II (2.5328(17) Å) and is substantially shorter than the sum of the covalent radii of Mn and Sn (2.78 Å). The Sn-S bond is noticeably lengthened (2.5217(11) Å) only for the S atom bound to tungsten (W-S, 2.5696(12) Å), while the other Sn-S bonds (2.4413(12) and 2.4291(12) Å) are virtually the same as in complex II (on average, 2.441 Å). Complex V contains the direct W-W bond (2.8153(16) Å) supplemented with four benzeneselenolate bridges in which the W-Se bonds (on average, 2.642(2) Å) are longer than the two terminal W-SePh bonds (2.571(2) Å). All the W-Se bonds are much shorter than the sum of the covalent radii of W and Se (2.82 Å).     

Syntheses and structures of tris(<Emphasis Type="Italic">para</Emphasis>-tolyl)-, tris(3-fluorophenyl)-, and tris(4-fluorophenyl)antimony dioximates

Tris(para-tolyl)antimony bis(2-oxybenzaldoximate) (I), tris(para-tolyl)antimony bis(2-nitrobenzaldoximate) (II), tris(para-tolyl)antimony bis(2-bromobenzaldoximate) (III), tris(3-fluorophenyl)antimony bis(2-oxybenzaldoximate) (IV), tris(4-fluorophenyl)antimony bis(2-bromobenzaldoximate) (V), and tris(4-fluorophenyl)antimony bis(2-nitrobenzaldoximate) (VI) are synthesized by the reactions of tris(paratolyl)-, tris(3-fluorophenyl)-, and tris(4-fluorophenyl)antimony with 2-oxy-, 2-nitro-, and 2-bromobenzaldoxime in diethyl ether in the presence of tert-butyl hydroperoxide. The Sb atoms in complexes I–VI have a distorted trigonal bipyramidal coordination mode with the oximate ligands in the axial positions. CIF files CCDC nos. 1062231 (I), 1059962 (II), 1465384 (III), 1465109 (IV), 1471948 (V), and 1060387 (VI).     

Mono-, Di- and Tetranuclear Complexes and Clusters With Bromine-Functionalized Bis(diphenylphosphino)amine Ligands

We report the preparation of bromo-aryl functionalized bis(diphenylphosphino)amine ligands of the type Ph₂PNArPPh₂ (1, Ar = p-BrC₆H₄; 2, Ar = p-BrC₆H₄–C₆H₄) and their coordination properties. Mono- and dinuclear complexes were formed with Cu(I), Au(I), Pd(II), Pt(II) and tetranuclear cobalt carbonyl clusters were obtained. The crystal structures of [PdCl₂(1)] (3), [PdCl₂(2)] (4), [(AuCl)(μ-1)] (6), [Co₄(CO)₅(μ-CO)₃(μ-dppa)(μ-1)] (dppa = Ph₂PNHPPh₂) (8) and [Co₄(CO)₅(μ-CO)₃(μ-dppm)(μ-1)] (dppm = Ph₂PCH₂PPh₂) (9) have been determined by X-ray diffraction. Whereas the diphosphine ligands chelate the metal center in 3 and 4, and in the Pt(II) complex 5 which is analogous to 3, ligand 1 acts as a bridge in 6 where the separation between the two Au(I) centers is 3.0402(5) Å. In the tetranuclear clusters 8 and 9, and in the cluster 10 analogous to 9 with 2 as bridging ligand, two orthogonal Co–Co edges are bridged by a diphosphine ligand and each cobalt center is thus coordinated by one P donor. Complex 3 was shown to react with the Pd(0) complex [Pd(dba)₂] (dba = dibenzylideneacetone) to afford a tetranuclear complex resulting from both the insertion of Pd(0) into the ligand C–Br bond and Pd(II)/Pd(0) comproportionation to form a doubly ligand-bridged Pd(I)–Pd(I) core.     

Coordination assemblies of rigid–flexible 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl)propane ligands with MCl<Subscript>2</Subscript> (M = Fe,Co, Cu or Zn): structural diversity and mass spectra

Reactions of the rigid–flexible N-heterocycle 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl) propane (H₂L) with MCl₂ (M = Fe, Co, Cu or Zn) gave coordination complexes, {[Fe ₂ ^III Cl₄(H₂L)₂]·2Cl}·EtOH·H₂O (1), {[Co₃Cl₅(HL)]·H₂O} _n (2), {[Co₄Cl₄(H₂L)₂(H₂O)₄]·[CoCl₄]₂}·H₂O (3), [Cu₂Cl₃(HL)(H₂O)]₆·5H₂O (4), [Cu ₂ ^II Cu^ICl₄(HL)] _n (5), {[Zn₂Cl₂(L)H₂O]·H₂O} _n (6) and [Zn₄Cl₆(HL)₂] (7), which have been characterized by single-crystal X-ray diffraction. Structural analysis reveals that the pyridine triazole ligand attains versatile coordination modes in these complexes. Complexes 1, 3, 4 and 7 consist of 0D clusters with binuclear or tetranuclear units; complex 2 presents a 2D network accompanied by HL^? and chloride bridges; complexes 5 and 6 show 1D chains with [Cu₃] and [Zn₂] subunits. In addition, the electrospray ionization mass spectrometry properties of selected complexes were investigated, revealing the stabilities and structural states of these complexes in solution. These results indicate that H₂L is an excellent multiconnection linker for the construction of diverse coordination complexes.     

Syntheses and structural studies of the nickel(II) octahedral complexes Ni(N∩N)<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>L<Subscript>2</Subscript> with nitrogen-containing and carboxylate ligands

A series of new mononuclear octahedral nickel(II) complexes with the Ni(N∩N) _x L₂ framework (x = 2 or 3, N∩N = Рhen (1,10-phenanthroline), AMPy (2-(aminomethyl)pyridine), L is H₂O, anions of carboxylic acids (CF₃CO₂?, CCl₃CO₂?, HCO₂?), chloride ion, and water) is synthesized and described by IR spectroscopy, mass spectrometry, elemental analysis, and X-ray diffraction analysis: [Ni(Рhen)₂(OH₂)Cl]Cl · 2H₂O (I), [Ni(Рhen)₂(OH₂)(O₂CCF₃)](O₂CCF₃) (II, IIa), [Ni(Рhen)₂(HCOO)_1.618(H₂O)_0.382](HCOO)_0.382 · 4.618H₂O (III), ([Ni(Рhen)₂(OH₂)₂](O₂CCCl₃)₂ · 6.2H₂O (IV), [Ni(AMPy)₂(OH₂)₂](HCO₂)₂ · 6H₂O (V), and [Ni(Рhen)₃](CCl₃COO)₂ · 7H₂O (VI). The subunit containing two formate ligands in the inner sphere of the [Ni(Рhen)₂(HCO₂)₂] complex prevails in the crystal structure of complex III, which is not characteristic of the nickel carboxylate complexes of this type. In aqueous solutions complex IV undergoes decarboxylation to form [Ni(Рhen)₂(CO₃)] · 7H₂O. A change in the nature of the N-donor ligands in Ni(N∩N)₂L₂ leads to the change (cis or trans) in the configuration of the whole complex (СIF files CCDC no. 880414 (I), 842336 (II), 1430414 (IIa), 1478111 (III), 1430430 (IV), 1443133 (V), and 1430415 (VI)).     

Ring-opening polymerization of ε-caprolactone catalysed by (pyridyl)benzoazole Zn(II) and Cu(II) complexes

This paper describes the synthesis of (pyridyl)benzoazole Zn(II) and Cu(II) complexes and their applications as catalysts in ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). Reactions of 2-(3-pyridyl)-1H-benzimidazole (L1), 2-(2-pyridyl)-1H-benzothiazole (L2) and 2-(2-pyridyl)-1H-benzimidazole (L3) with Zn(II) and Cu(II) acetates produced the corresponding complexes; [Zn₂(L1)₂(OAc)₄)] (1), [Cu₂(L1)₂(OAc)₄] (2), [Zn(L2)(OAc)₂)] (3), [Zn(L3)(OAc)₂)] (4) and [Cu(L3), (OAc)₂)] (5). Molecular structures of complexes 2 and 5a revealed that while L1 adopts a monodentate binding mode, through the pyridyl nitrogen atom, L3 exhibits a bidentate coordination mode. All the complexes formed active catalysts in the ROP of ε-CL to afford moderate molecular weight polymers. The kinetics of the ROP reactions of ε-CL were pseudo-first-order with respect to monomer and catalysts.     

New organophosphorus compounds containing nicotinamide: synthesis,structure and DFT calculations

Novel organophosphorus compounds, containing Nicotinamide, with formula C₅H₄NC(O)NHP(O)R₂, R=Cl (1), OH (2), N(C₂H₅)₂ (3), N(C₃H₇)₂ (4), N(n-C₄H₉)₂ (5), NHC₃H₅ (6), NHC₅H₉ (7), were synthesized and characterized by ¹H, ¹³C, ³¹P, NMR, IR, spectroscopy and elemental analysis. Single crystal structures of 3 7 were determined by X-ray crystallography. ¹HNMR spectra of compounds 2, 3, 6–8 demonstrated interesting long-range coupling constant, ⁿ J _P,H (n = 5 7). Crystallographic data revealed that in both molecules 3 and 7, the phosphoryl and the carbonyl groups have anti-configurations and the phosphorus atoms in these structures have distorted tetrahedral configuration. All the hydrogen bonds and electrostatic interactions make a three dimensional polymeric network for both 3 and 7. Interestingly, two independent conformers were detected in the unit cell of compound 7. The two conformers of the title compound can be observed in a solid phase but only one compound defined in a solution. These two conformers are connected to each other by a short contact, N (amine)···H–C (pyridine) with 2.626 Å distance. The molecular geometry of 7 was calculated by DFT/B3LYP (6–31+G**) quantum chemical calculations. The computational optimized geometric parameters and vibrational frequencies showed a good agreement with the experimental results, considering reasonable variations arising from the differences between solid and gaseous phases. Theoretical calculations revealed that the more stable conformer of the title compound is conformer 1 with the energy of ?1335.723996 a.u., which is about 1.17 kcal/mol lower than the energy of conformer 2.     

Directed assembly of cobalt(II) 1-H-indazole-3-carboxylic acid coordination networks by bipyridine and its derivatives: structural versatility,electrochemical properties,and antifungal activity

This paper describes the hydrothermal synthesis, full characterization, and architectural diversity of three intriguingly bioactive cobalt–organic frameworks, namely, 3D [Co(HL ^? )₂(BPY)] _n ·4nH₂O (1), 2D [Co(HL ^? )₂(BPE)] _n (2), and 2D [Co(HL ^? )₂(DPP)] _n (3) coordination polymers, synthesized through a mixed ligand strategy using H ₂ L (1-H-indazole-3-carboxylic acid) as a main structural block and the flexible bipyridine and its derivatives (BPY = 4,4′-bipydine, BPE = 1,2-bis(4-pyridyl)ethane, DPP = 1,3-bis(4-pyridyl)propane) as auxiliary ligand sources. Complexes 1–3 were isolated as air stable and slightly soluble crystalline solids and characterized using elemental analysis, FT-IR, electrochemical technique, thermogravimetric analysis, powder X-ray diffractometer, and single-crystal X-ray crystallography. The bipyridine derivatives played key roles in defining the structural space group and dimensionality feature of the obtained networks. The abundant H-bonding and π–π stacking interactions in complexes 1–3 gave rise to their intricate metal–organic structures of 3D (1), 2D (2), and 2D (3). In addition, the solutions of complexes 1–3 showed profound antifungal activities against the selected strain of Colletotrichum musae compared with the controlled group using benomyl as a traditional agrochemical fungicide.     

Synthesis,characterization, and crystal structures of 2D cobalt(II) and nickel(II) coordination polymers containing flexible bis(benzimidazole) ligands

Three coordination polymers, namely {[Ni(L1)(nip)(H₂O)]·2H₂O} _n (1), [Co(L2)(tbip)] _n (2), and {[Co₂(L3)₂(bptc)]·3H₂O} _n (3) (L1 = 1,4-bis(5,6-dimethylbenzimidazole)butane, L2 = 1,4-bis(5,6-dimethylbenzimidazole)-2-butylene, L3 = 1,3-bis(5,6-dimethylbenzimidazole)propane, H₂nip = 5-nitro-isophthalic acid, H₂tbip = 5-tert-butyl-isophthalic acid, H₄bptc = biphenyl-3,3′,4,4′-tetracarboxylic acid), have been synthesized under hydrothermal conditions and characterized by physicochemical and spectroscopic methods as well as by single-crystal X-ray diffraction analysis. Complexes 1 and 2 both feature a two-dimensional (4,4) layer with (4⁴ × 6²) topology. Complex 3 possesses a uninodal 4-connected 2D htb network. The fluorescence spectra and catalytic properties of the complexes for the degradation of methyl orange by sodium persulfate in a Fenton-like process are reported.     

Aluminum hydrides with radical-anionic and dianionic acenaphthene-1,2-diimine ligands

The reaction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with LiAlH₄ affords two products regardless of the solvent used (tetrahydrofuran or diethyl ether). These products were isolated as green and colorless crystals. Green crystals of the complex [(dpp-bian)Al(H)₂Li(THF)₃] (1) were obtained from tetrahydrofuran; colorless crystals of the complex [{dpp-bian(H₂)}Al(H)₂Li(Et₂O)₂] (2), from diethyl ether. The reactions of compound 1 with 2,6-di-tert-butyl-4-methylphenol and benzophenone gave monohydrides [(dpp-bian)Al(H)(OC₆H₂-2,6-Bu₂ ^t-4-Me)][Li(THF)₄] (3) and [(dpp-bian)Al(H)(OCHPh₂)- Li(THF)₂] (4), respectively. The diamagnetic aluminum hydride [(dpp-bian)AlH(THF)] (5) was synthesized by the reaction of dichloroalane HAlCl₂ (in situ) with the disodium salt of dpp-bian in THF; the paramagnetic hydride [(dpp-bian)AlH(Cl)] (6) containing the dpp-bian radical anion was synthesized by the reaction of the monosodium salt (dpp-bian)Na with monochloroalane H₂AlCl (in situ) in diethyl ether. The reaction of compound 6 with tert-butyllithium gives the complex [(dpp-bian)AlBu^t(Et₂O)] (7). Diamagnetic derivatives 1—5 and 7 were characterized by ¹Н NMR spectroscopy; paramagnetic compound 6, by ESR spectroscopy. The molecular structures of compounds 1—7 were determined by single-crystal X-ray diffraction.     

Syntheses,Crystal Structures,and Luminescence Properties of Co(II), Ni(II) and Zn(II) Complexes with 4′-(4-(Imidazol-1-Yl)phenyl)-2,2′:6′,2″-Terpyridine

Three coordination complexes [Co(Imphtpy)₂]Cl₂ · CHCl₃ · 3H₂O (I), [Ni(Imphtpy)₂]Cl₂ · CHCl₃ · C₂H₅OH (II) and [Zn(Imphtpy)]Cl₂ (III) (Imphtpy = 4'-(4-(imidazol-1-yl)phenyl)2,2':6',2″-terpyridine) have been synthesized and characterized by IR, elemental analysis and X-ray single crystal diffraction (СIF files CCDC nos. 1012055 (I), 1011708 (II), 1011709 (III)). Complexes I and II are isomorphism except for some solvent molecules. In the crystal, both face-to-face interactions between pyridyl ring, imidazole rings and phenyl rings and hydrogen bonds facilitate the construction of 3D networks. There are no hydrogen bonds in III and the packing of discrete neutral molecules were ascribed to face-to-face interactions and van der Waals forces. The luminescence properties of three complexes have been investigated in the solid state at room temperature.     

Copper oxalate complexes: synthesis and structural characterisation

Six copper(II) oxalate complexes, namely {K₂[Cu(ox)₂]} _n (1), {(Hiz)₂[Cu(ox)₂]} _n (2), {[Cu(ox) (N-Bzliz)₂]} _n (3), (HMeiz)₂[Cu(ox)₂] (4), {[Cu(ox)(Meiz)₂]} _n (5), and [Cu(Hox)₂(H₂O)₂](N-Bzliz) (6) where ox = oxalate ion, iz = imidazole, N-Bzliz = N-benzylimidazole, Meiz = 2-methylimidazole, were synthesised and characterised by single crystal X-ray diffraction (complexes 1–5) or powder X-ray diffraction (compound 6). The three-dimensional crystal packing structures of 2, 4, and 5 are consolidated by intermolecular hydrogen bonds linking the oxygen atom of the oxalate group and the amine or imine group of the imidazole-based part into chains. The molecules of complex 6 are held together by intermolecular hydrogen bonds between the oxygen atoms of the oxalate group and coordinated water molecules.