Synthesis and crystal structure determination of Cl-substituted iridium(III) acetylacetonate

γ-Halogen-substituted iridium(III) acetylacetonates of general formula Ir(acacX)₃,where acacX = CH₃ -CO-CX-CO- CH₃,X =Br, I, were synthesized. The compounds are characterized by melting points and chemical analysis data for C, H, Br, and I. An X-ray diffraction analysis was performed for iridium(III) acetylacetonate and its y-substituted analogs, crystal data were obtained, and crystal structures were determined. The crystals are monoclinic;the structures are molecular. Crystal data: Ir(acac)3 _- IrO₆C₁₅H₂₁,a = 13.900(2), b = 16.440(3), c = 7.494(2) ?, γ =98.63(2)‡, V= 1693.2 ?³,space group P2₁/b,Z = 4, d_calc =1.92 g/cm³,sin θ/λ_max = 0.703, F_hkl = 2841, R = 0.044. Ir(acacBr)_3- IrBr₃O₆C₁₅H₁₈,a = 12.794(2), b = 15.753(2), c = 9.990(2) ? Β = 105.76(2)‡, V= 1937.6 ?³,space group P2₁/n,Z =4, d_calc =2.49 g/cm³, sinθ/λ_max = 0.702, F_hkl = 1748, R = 0.048. Ir(acacI)3- M₃O₆C₁₅H₁₈,a = 12.855(2), b = 10.136(2), c =16.338(3)?, Β = 104.6(2)‡, V=2059.8?³,space group P2₁/n, Z =4, d_calc = 2.79g/cm³, θ_max =25‡, F_hkl = 2817, R =0.032. The Ir..Ir distances were estimated to be > 7.49 ? for Ir(acac)3 and > 8.10 ? for Ir(acacBr)3 and Ir(acacl)₃.If the estimate is limited to 10 ?, the intermolecular coordination number (ICN) in the structures is 10. Translated fromZhurnal Struktumoi Khimii, Vol. 40, No. 2, pp. 331–339, March–April, 1999     

Synthesis and crystal structure determination of iridium(III) acetylacetonate and its Br-and I-substituted analogs

γ-Halogen-substituted iridium(III) acetylacetonates of general formula Ir(acacX)₃,where acacX = CH₃ -CO-CX-CO- CH₃,X =Br, I, were synthesized. The compounds are characterized by melting points and chemical analysis data for C, H, Br, and I. An X-ray diffraction analysis was performed for iridium(III) acetylacetonate and its y-substituted analogs, crystal data were obtained, and crystal structures were determined. The crystals are monoclinic;the structures are molecular. Crystal data: Ir(acac)3 _- IrO₆C₁₅H₂₁,a = 13.900(2), b = 16.440(3), c = 7.494(2) å, γ =98.63(2)?, V= 1693.2 å³,space group P2₁/b,Z = 4, d_calc =1.92 g/cm³,sin θ/λ_max = 0.703, F_hkl = 2841, R = 0.044. Ir(acacBr)_3- IrBr₃O₆C₁₅H₁₈,a = 12.794(2), b = 15.753(2), c = 9.990(2) å Β = 105.76(2)?, V= 1937.6 å³,space group P2₁/n,Z =4, d_calc =2.49 g/cm³, sinθ/λ_max = 0.702, F_hkl = 1748, R = 0.048. Ir(acacI)3- M₃O₆C₁₅H₁₈,a = 12.855(2), b = 10.136(2), c =16.338(3)å, Β = 104.6(2)?, V=2059.8å³,space group P2₁/n, Z =4, d_calc = 2.79g/cm³, θ_max =25?, F_hkl = 2817, R =0.032. The Ir..Ir distances were estimated to be > 7.49 å for Ir(acac)3 and > 8.10 å for Ir(acacBr)3 and Ir(acacl)₃.If the estimate is limited to 10 å, the intermolecular coordination number (ICN) in the structures is 10.     

Synthesis and characterization of half-sandwich iridium(III) and rhodium(III) complexes bearing organochalcogen ligands

Reactions of [Cp*M(μ-Cl)Cl]₂ (M = Ir, Rh; Cp* = η⁵-pentamethylcyclopentadienyl) with bi- or tri-dentate organochalcogen ligands Mbit (L1), Mbpit (L2), Mbbit (L3) and [Tm^Me]⁻ (L4) (Mbit = 1,1′-methylenebis(3-methyl-imidazole-2-thione); Mbpit = 1,1′-methylene bis (3-iso-propyl-imidazole-2-thione), Mbbit = 1,1′-methylene bis (3-tert-butyl-imidazole-2-thione)) and [Tm^Me]⁻ (Tm^Me = tris (2-mercapto-1-methylimidazolyl) borate) result in the formation of the 18-electron half-sandwich complexes [Cp*M(Mbit)Cl]Cl (M = Ir, 1a; M = Rh, 1b), [Cp*M(Mbpit)Cl]Cl (M = Ir, 2a; M = Rh, 2b), [Cp*M(Mbbit)Cl]Cl (M = Ir, 3a; M = Rh, 3b) and [Cp*M(Tm^Me)]Cl (M = Ir, 4a; M = Rh, 4b), respectively. All complexes have been characterized by elemental analysis, NMR and IR spectra. The molecular structures of 1a, 2b and 4a have been determined by X-ray crystallography.     

Synthesis and phosphorescent properties of two novel iridium (Ⅲ) complexes bearing bulky tert-butyl substituents

The synthesis and phosphorescence properties of two novel Ir(Ⅲ)complexes bearing tert-butyl substituents,bis(4-tert-butyl-2- phenylbenzothiozolato-N,C~(2′))iridium(Ⅲ)(acetylacetonate)[(tbt)_2Ir(acac)]and bis(4-tert-butyl-1-phenyl-1H-benzimidazolato- N,C~(2′))iridium(Ⅲ)(acetylacetonate)[(tpbi)_2Ir(acac)],are reported,their molecular structures are confirmed by~1H NMR,ESI-MS and elementary analysis.Photoluminescence(PL)studies revealed that they can emit strong green and orange phosphorescence in high quantum yields.Compared to their prototypes lacking of tert-butyl substituents,the two novel iridium(Ⅲ)complexes both have shorter lifetimes and improved or nearly similar PL quantum efficiencies,implying that the exciton quenching is inhibited effectively when molecular steric hindrance increases.The two chelates have great potential to be used as electrophosphorescent materials.     

Enhanced luminescent iridium(III) complexes bearing aryltriazole cyclometallated ligands

Herein we report the synthesis of 4-aryl-1-benzyl-1H-1,2,3-triazoles (atl), made via "Click chemistry" and their incorporation as cyclometallating ligands into new heteroleptic iridium(III) complexes containing diimine (N(^)N) ancillary ligands 2,2'-bipyridine (bpy) and 4,4'-di-tert-butyl-2,2'-bipyridine (dtBubpy). Depending on decoration, these complexes emit from the yellow to sky blue in acetonitrile (ACN) solution at room temperature (RT). Their emission energies are slightly blue-shifted and their photoluminescent quantum efficiencies are markedly higher (between 25 and 80%) than analogous (C(^)N)(2)Ir(N(^)N)(+) type complexes, where C(^)N is a decorated 2-phenylpyridinato ligand. This increased brilliance is in part due to the presence of the benzyl groups, which act to sterically shield the iridium metal center. X-ray crystallographic analyses of two of the atl complexes corroborate this assertion. Their electrochemistry is reversible, thus making these complexes amenable for inclusion in light-emitting electrochemical cells (LEECs). A parallel computational investigation supports the experimental findings and demonstrates that for all complexes included in this study, the highest occupied molecular orbital (HOMO) is located on both the aryl fragment of the atl ligands and the iridium metal while the lowest unoccupied molecular orbital (LUMO) is located essentially exclusively on the ancillary ligand.     

Square-planar iridium(II) and iridium(III) amido complexes stabilized by a PNP pincer ligand

Squaring the circle: the novel dienamido pincer ligand N(CHCHPtBu(2))(2)(-) affords the isolation of the unusual square-planar iridium(II) and iridium(III) amido complexes [IrCl{N(CHCHPtBu(2))(2)}](n) (n=0 (1), +1 (2)). In contrast, the corresponding iridium(I) complex of the redox series (n=-1) is surprisingly unstable. The diamagnetism of 2 is attributed to strong N→Ir π donation.     

Synthesis,structures, and properties of iridium(III) bis-cyclometallated complexes containing three-atom chelates

Heating of [Ir(η²-ppy)₂(MeCN)₂]NO₃ (1, ppy = 2-phenylpyridine) in MeCN under reflux afforded [Ir(η²-ppy)₂(η²-NO₃)] (2). Treatment of 1 with 2-mercaptopyridine (Hmp), 6-methyl-2-hydroxypyridine (Hmhp), 6-chloro-2-hydroxypyridine (Hchp), trimethylacetic acid (Htma), benzoic acid (Hbz), 2-methylacrylic acid (Hma), and acetic acid (Hac) in the presence of excess Et₃N produced [Ir(η²-ppy)₂(η²-XZY)] (XZY^? = mp^? (3), mhp^? (4), chp^? (5), ac^? (6), bz^? (7), ma^? (8), tma^? (9)). Crystal structures of 2, 3, 7, 8, and 9 have been characterized by X-ray diffraction. The inherent strain contained in the four-member rings, {Ir(η²-XZY)}, is apparently reflected in the long Ir–X and Ir–Y distances. The absorption and emission properties of nearly all the new complexes except 2 show small variations.     

Synthesis and electronic characterization of bipyridine dithiolate rhodium(III) complexes

Five new mixed diimine 1,1'-dithiolate or dithiocarbamate ligand complexes of the form [Rh(bpy)2(SS)][PF6]n, where bpy = 2,2'-bipyridine and SS = various substituted dialkyldithiocarbamates or 1,1'-dithiolates, were synthesized from cis-[Rh(bpy)2(OTf)2][OTf]. The triflate ligands are easily displaced by other ligands and allow these syntheses to proceed in high yields (80-90% overall) under relatively mild reaction conditions and to give high purity products. Electrochemistry shows irreversible two-electron reduction of Rh(III) to Rh(I) and a concomitant loss of one bipyridine ligand; this is followed by reversible one-electron reduction of the remaining 2,2'-bipyridine ligand. The electronic characterizations of these complexes are consistent with significant delocalization of the sulfur electron density onto the empty metal d orbitals. The 1,1'-dithiolate ligands induce larger red shifts in the absorption and emission spectra than the dithiocarbamates as the 1,1'-dithiolates have a more extensive conjugation system.     

Synthesis,crystal structures and spectroscopic studies of praseodymium(III) malonate complexes

Reactions of malonic acid (H₂mal) with PrCl₃·6H₂O afforded the known complex [Pr₂(mal)₃(H₂O)₆]_n (1), and compounds [Pr₂(mal)₃(H₂O)₆]_n·2nH₂O (2·2nH₂O), [PrCl(mal)(H₂O)₃]_n·0.5nH₂O (3·0.5nH₂O) and [Pr(mal)(Hmal)(H₂O)₃]_n·nH₂O (4·nH₂O) using various reaction ratios, reaction media (H₂O, MeOH) and pH values. Analogous reactions with CeCl₃·7H₂O afforded compounds [Ce₂(mal)₃(H₂O)₆]_n (5), [CeCl(mal)(H₂O)₃]_n·nH₂O (6·nH₂O) and [Ce(mal)(Hmal)(H₂O)₃]_n·nH₂O (7·nH₂O). Compounds 2·2nH₂O and 3·0.5nH₂O were characterized by X-ray crystallography, and 4–7 by microanalytical and spectroscopic data. The malonate(-2) ligand adopts three different coordination modes in the structures of 1–3, i.e., the μ₂-κO:κO′:κO″ and the μ₄-κ²O:κO′:κ²O″:κO? in 1 and 2 leading to a 3D network structure, and the μ₃-κ²O:κO′:κ²O″:κO? in 3 promoting an 1D structure. The thermal decomposition of 1 and 3·0.5nH₂O was monitored by TG/DTA and TG/DTG measurements. The structural features of 1–3 are discussed in terms of known malonato(-2) Ln^III and Ca^II complexes. The bioinorganic chemistry relevance of our results is discussed.     

Synthesis, crystal structures and DNA-binding properties of two new mononuclear copper(II) complexes

Two mononuclear copper(II) complexes, [Cu(bpy)₂(CH₃OH)](pic)₂ (1) and [Cu(Me₂bpy)₂(H₂O)](pic)₂ (2) (bpy = 2,2′-bipyridine; Me₂bpy = 4,4′-dimethyl-2,2′-bipyridine; Hpic = 2,4,6-trinitrophenol), were synthesized and characterized by elemental analyses, conductivity measurements, IR, UV–Visible spectroscopy and single crystal X-ray analyses. Both complexes 1 and 2 are mononuclear compounds. The copper atom in complex 1 is in a distorted square pyramidal geometry with a CuN₄O chromophore as revealed from the τ value (0.25), while the Cu(II) ion in complex 2 displays a distorted trigonal bipyramidal stereochemistry with τ = 0.72. Hydrogen bonding interactions and π–π stacking interactions link the mononuclear copper complex 1 or 2 into a 1D infinite chain. The interactions of the two mononuclear complexes with herring sperm DNA (HS-DNA) have been studied by UV–visible absorption titration, fluorescence titration and ethidium bromide (EB) displacement experiments. The results suggest that both complexes might bind to DNA by intercalation.     

Synthesis,crystal structures,and characterization of copper(II) carboxylate complexes incorporating 1,10-phenanthroline and bipyridine

A series of Cu(II) carboxylate complexes (carboxylate?=?2-fluorobenzoic acid (2-HFBA) or 4-fluorobenzoic acid (4-HFBA)) containing either one chelating 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and thermal analyses. In [Cu(bipy)(H₂O)(2-FBA)₂] (1), [Cu(bipy)(H₂O)(4-FBA)₂] (3), and [Cu(phen)(H₂O)(2-FBA)₂] (4), Cu is five-coordinate in a square pyramidal geometry and four-coordinate in [Cu(phen)(2-FBA)₂] (2). The four complexes are extended into 1-D chains through hydrogen-bonding and π?···?π interactions in 1 and 4, only hydrogen-bonding in 2, and π?···?π interactions in 3. These contacts lead to aggregation and supramolecular self-assembly.     

Synthesis,crystal structures,spectroscopic studies and antibacterial properties of a series of mononuclear cobalt(III) Schiff base complexes

New complexes of cobalt(III) with the tridentate and tetradentate Schiff base ligands: 3-methoxy-2-{(Z)[(2-hydroxyphenyl)imino]methyl}phenol (H₂L¹), 4-[(2-hydroxyphenyl)imino]-2-pentanone (H₂L²); and 2-((E)-1-(2-((E)-1-(2-hydroxy-4,5-dimethylphenyl)ethylideneamino)ethylimino)ethyl)-4,5 dimethylphenol (H₂L³), namely [Co^III(L¹)(N-MeIm)₃]PF₆ (1), [Co^III(L¹)(py)₃]ClO₄ (2), [Co(L¹)(py)₃][Co(L¹)₂] (3) and [Co^III(L²)(N-MeIm)₃]PF₆ (4) and [Co(L³)(N-MeIm)₂]PF₆ (5), were synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structures of the complexes were determined by X-ray crystallography. In each of these complexes, the cobalt(III) centre has a slightly distorted octahedral environment, utilizing all available coordination centres of the ligands. The complexes were also screened for in vitro antibacterial activities against four human pathogenic bacteria, and their minimum inhibitory concentrations indicated good antibacterial activities.     

Cyclometallated ionic iridium(III) binuclear complexes with a bisphenanthroline bridging ligand: Synthesis and photophysical properties

New iridium(III) ionic binuclear complexes, in which iridium-containing cyclometallated fragments are bound by a bridging bisphenanthroline ligand were synthesized. The compounds obtained show intensive photoluminescence of yellow and yellow-green colors.     

Synthesis and X-ray crystal structures of two cobalt(III) complexes with Schiff bases

Two new mononuclear cobalt(III) complexes, [Co(MP)₂(N₃)] (I) and [Co(BP)₂]NO₃ · 2H₂O (II), where MP is 2-methoxy-6-[(2-morpholin-4-ylethylimino)methyl]phenolate and BP is 4-bromo-2-[(2-methylaminoethylimino)methyl]phenolate, were prepared and structurally characterized by physicochemical methods and single crystal X-ray diffraction. Both complexes crystallize in the monoclinic space group P2₁/c. For I: a = 10.3526(18), b = 25.371(4), c = 11.3585(19) Å, β = 101.529(8)°, V = 2923.1(8) ų, Z = 4; for II: a = 9.801(2), b = 27.183(3), c = 10.846(2) Å, β = 114.269(2)°, V = 2634.2(8) ų, Z = 4. An X-ray structural analysis indicates that in both complexes the Co atoms adopt octahedral coordination. The hindrance effects of the Schiff bases can influence the coordination of the secondary ligands such as azide.     

Synthesis and crystal structures of Schiff base zinc(III) complexes with antibacterial activity

Two halide-coordinated zinc(II) complexes with the Schiff base 2-ethoxy-6-[(2-piperidin-1-ylethylimino)methyl]phenol were synthesized and structurally characterized by elemental analysis (C, H, N), FT-IR spectra, and single-crystal X-ray diffraction. The Zn atom in each complex is four-coordinated in a tetrahedral geometry by one phenolic O and one imine N atoms of the Schiff base ligand and by two halide atoms. The antibacterial activity of the complexes and the Schiff bases against the bacteria Staphylococcus aureus, Bacillus anthracis, Pseudomonas aeruginosa, and Streptococcus agalactiae was investigated.     

Synthesis and crystal structures of cobalt(III) and zinc(II) complexes with Schiff bases

Two new cobalt(III) and zinc(II) complexes, [Co(L¹)₂ (H₂O)] · ClO₄ (I) and [Ni(L²)₂ (H₂O)₂] · 2ClO₄ (II), where L¹ is the deprotonated form of 5-methoxy-2-[(2-morpholin-4-ylethylimino)methyl]phenol, and L² is the zwitterionic form of 2-[(2-isopropylaminoethylimino)methyl]-5-methoxyphenol, were synthesized and structurally characterized by elemental analyses, IR spectra, and single-crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/c, a = 11.1512(4), b = 28.2424(11), c = 10.9655(4) Å, β = 95.746(2)°, V = 3436.1(2) ų, Z = 4. The crystal of II is triclinic: space group P2₁/c, a = 8.1441(2), b = 10.4531(3), c = 10.8849(3) Å, α = 84.0240(10)°, β = 76.9800(10)°, γ = 74.2280(10)°, V = 867.92(4) ų, Z = 1. Complex I consists of a mononuclear cobalt(III) complex cation and a perchlorate anion. Complex II consists of a crystallographic centrosymmetric mononuclear nickel(II) complex cation and two perchlorate anions. Each metal atom in the complexes is in an octahedral coordination.     

Stepwise formation of quasi-octahedral macrocyclic complexes of rhodium(III) and iridium(III) bearing a pentamethylcyclopentadienyl group

Reactions of [[MCl2(Cp*)]2] (1: M=Ir, 2: M=Rh) with bidentate ligands (L) such as 1,4-diisocyano-2,5-dimethylbenzene (a), 1,4-diisocyano-2,3,5,6-tetramethylbenzene (b), pyrazine (c) or 4,4'-dipyridyl (d) gave the corresponding dinuclear complexes [[MCl2(Cp*)]2(L)] (M=Ir: 3a, 3b, 5c, 5d; M=Rh: 4b, 6c, 6d), which were converted into tetranuclear complexes [[M2(mu-Cl)2(Cp*)2]2(L)2](OTf)4 (M=Ir: 7c, 7d, 9a, 9b; M=Rh: 8e, 8d, 10b) on treatment with Ag(OTf). X-ray analyses of 8c and 8d revealed that each of four pentamethylcyclopentadienyl metal moieties was connected by two mu-Cl-bridged atoms and a bidentate ligand to construct a rectangular cavity with the dimensions of 3.7 x 7.0 A for 8c and 3.7 x 11.5 A for 8d. Both the Rh2Cl2 and pyrazine (or 4,4'dipyridyl) ring planes are perpendicular to the Rh4 plane. Treatment of Cl-bridged complexes (7c, 7d, 8e, 8d, 9b, and 10b) with a different ligand (L') resulted in cleavage of the Cl bridges to produce two-dimensional complexes [[MCl(Cp*)]4[(L)-(L')]2](OTf)4 (11ac, 11bc, 11bd, 12bc, and 12bd) with two different ligand "edges". Complex 10b reacted readily with 1,4-diisocyano-2,3,5,6-tetramethylbenzene (b) to give a tetranuclear rhodium(III) complex 12bb. The structure of tetranuclear complexes was confirmed by X-ray analysis of 11bc. Each [MCp*] moiety is surrounded by a Cl atom, isocyanide, and pyrazine (or 4,4'-dipyridyl) and the dimensions of its cavity are 7.0 x 11.6 A.     

Bis-cyclometalated iridium(III) complexes bearing ancillary guanidinate ligands. Synthesis, structure, and highly efficient electroluminescence

We report the synthesis, structure, and photophysical and electroluminescent (EL) properties of a series of heteroleptic bis(pyridylphenyl)iridium(III) complexes with various ancillary guanidinate ligands. The reaction of the bis(pyridylphenyl)iridium(III) chloride [(ppy)(2)Ir(μ-Cl)](2) with the lithium salt of various guanidine ligands Li{(N(i)Pr)(2)C(NR(1)R(2))} at 80 °C gave in 60-80% yield the corresponding heteroleptic bis(pyridylphenyl)/guanidinate iridium(III) complexes having a general formula of [(ppy)(2)Ir{(N(i)Pr)(2)C(NR(1)R(2))}], where NR(1)R(2) = NPh(2) (1), N(C(6)H(4)(t)Bu-4)(2) (2), carbazolyl (3), 3,6-bis(tert-butyl)carbazolyl (4), N(C(6)H(4))(2)S (5), N(C(6)H(4))(2)O (6), indolyl (7), NEt(2) (8), N(i)Pr(2) (9), N(i)Bu(2) (10), and N(SiMe(3))(2) (11). These heteroleptic cyclometalated (C^N) iridium(III) complexes showed intense absorption bands in the UV region assignable to π-π* transitions and weaker metal-to-ligand charge-transfer transitions extending to the visible region. These complexes also showed intense emissions at room temperature. Their photoluminescence spectra were influenced to some extent by the ancillary guanidinate ligands, giving λ(max) values in the range of 528-560 nm with quantum yields (Φ) of 0.16-0.37 and lifetimes of 0.61-1.43 μs. Organic light-emitting diodes were fabricated by the use of these complexes as dopants in various concentrations (5-100%) in a N,N'-dicarbazolylbiphenyl host. High current efficiency (η(c); up to 137.4 cd/A) and power efficiency (η(p); up to 45.7 lm/W) were observed under appropriate conditions. Their high EL efficiency may result from efficient trapping and radiative relaxation of the excitons formed in the EL process. Because of the steric hindrance of the guanidinate ligands, no significant intermolecular interaction was observed in these complexes, thus leading to the reduction of self-quenching and triplet-triplet annihilation at high currents. The EL emission color could be changed in the range of green to yellow by choosing appropriate guanidinate ligands.     

Synthesis, crystal structures, and properties of oxovanadium(IV)-lanthanide(III) heteronuclear complexes

A new series of oxovanadium(IV)-lanthanide(III) heteronuclear complexes [Yb(H2O)8]2[(VO)2(TTHA)](3)21 H2O (1), {[Ho(H2O)7(VO)2(TTHA)][(VO)2(TTHA)](0.5)} 8.5 H2O (2), {[Gd(H2O)7(VO)2(TTHA)][(VO)2(TTHA)](0.5)}8.5 H2O (3), {[Eu(H2O)7][(VO)2(TTHA)](1.5)} 10.5 H2O (4), and [Pr2(H2O)6(SO4)2][(VO)2(TTHA)] (5) (H6TTHA=triethylenetetraaminehexaacetic acid) were prepared by using the bulky flexible organic acid H(6)TTHA as structure-directing agent. X-ray crystallographic studies reveal that they contain the same [(VO)2(TTHA)]2- unit as building block, but the Ln3+ ion lies in different coordination environments. Although the lanthanide ions always exhibit similar chemical behavior, the structures of the complexes are not homologous. Compound 1 is composed of a [Yb(H2O)8]3+ ion and a [(VO)2(TTHA)]2- ion. Compounds 2 and 3 are isomorphous; both contain a trinuclear [Ln(H2O)7(VO)2(TTHA)]+ (Ln=Ho for 2 and Gd for 3) ion and a [(VO)2(TTHA)]2- ion. Compound 4 is an extended one-dimensional chain, in which each Eu3+ ion links two [(VO)2(TTHA)]2- ions. For 5, the structure is further assembled into a three-dimensional network with an interesting framework topology comprising V2Pr2 and V4Pr2 heterometallic lattices. Moreover, 4 and 5 are the first oxovanadium(IV)-lanthanide(III) coordination polymers and thus enlarge the realm of 3d-4f complexes. The IR, UV/Vis, and EPR spectra and the magnetic properties of the heterometallic complexes were studied. Notably, 2 shows unusual ferromagnetic interactions between the VO2+ and Ho3+ ions.     

Synthesis and structural studies of novel aminopolychloroethylated chelate acetylacetonate complexes of aluminum (III) and chromium (III)

Structural Chemistry - Novel bio-medicinally promising complexes of amidotrichloroethylated acetylacetonate with Cr(III) and Al(III), which combine synthetically and pharmacologically attractive...