Bis(2-Amino-5-bromopyrimidinium) Tetrahalometallates: Crystal structures of (2-amino-5-bromopyrimidinium)2 MCl4 (M = Co,Zn)

The reactions of metal(II) chlorides and bromides with 2-amino-5-bromopyrimidine (2-abpm) in neutral and acidic solution were investigated. The reaction with ZnCl₂, ZnBr₂, CoCl₂, CoBr₂ and MnCl₂ in acidic nitromethane solution gave complexes of the formula (2-abpmH)₂MX₄ (1, M?=?Zn, X?=?Cl; 2, M?=?Zn, X?=?Br; 3, M?=?Co, X?=?Cl; 4, M?=?Co, X?=?Br; 5, M?=?Mn, X?=?Cl). Crystals of 1 and 3 suitable for single crystal X-ray diffraction were obtained. Crystal data: For (1): triclinic, P-1, a?=?6.2485(13), b?=?9.0520(14), c?=?15.334(4)?Å, α?=?94.81(2), β?=?95.224(17), γ?=?98.027(17)°, V?=?851.1(3)?ų, Z?=?2, R?=?0.0596 for [|I|?≥?2σ(I)]. For (3): triclinic, P-1, a?=?6.2438(13), b?=?9.0597(15), c?=?15.318(3)?Å, α?=?94.749(18), β?=?95.343(15), γ?=?98.021(17)°, V?=?850.2(3)?ų, Z?=?2, R?=?0.0452 for [|I|?≥?2σ(I) ]. Variable temperature magnetic susceptibility data indicates weak antiferromagnetic interactions in the cobalt and manganese complexes.     

Copper(II) halide salts and complexes of 4-amino-2-fluoropyridine: synthesis,structure and magnetic properties

Reaction of 4-amino-2-fluoropyridine (2-F-4-AP) with copper halides produced the neutral coordination complexes: (2-F-4-AP)₂CuX₂ (X = Cl(1), Br(2)). 1 crystallizes in the orthorhombic space group Pccn in a distorted square planar geometry. Magnetic susceptibility data were fit to the uniform chain Heisenberg model resulting in C = 0.439(6)emu-K/mole-Oe and J = ?28(1) K. 2 crystallizes in the monoclinic space group C2/m and is closer to distorted tetrahedral. Intermolecular Br?Cu contacts generate a square layer. Magnetic data show very weak ferromagnetic interactions [C = 0.42(1)emu-K/mol-Oe, J = 0.71(2) K]. Similarly, reaction of 2-F-4-AP with copper halides and aqueous HX in alcohol solvents produced the salts (2-F-4-APH)₂CuX₄ (X = Cl(3), Br(4)). 3 crystallizes in the triclinic space group P-1. Crystal packing reveals short Cl?Cl contacts which generate a structural ladder. However, analysis of the magnetic data suggests that only the rails of the ladder produce a viable magnetic superexchange pathway; the uniform Heisenberg chain model provides C = 0.449(1)emu-K/mol-Oe and J = -6.9(1) K. 4 is isostructural and is also best fit by a chain model [J = ?2.7(4) K]. The brominated complex (2-F-3-Br-4-APH)₂CuBr₄·2H₂O, 5, (2-F-3-Br-4-APH = 4-amino-3-bromo-2-fluoropyridinium) was serendipitously produced as a byproduct of the synthesis of 4 and was characterized by single-crystal X-ray diffraction.     

Transition metal complexes of 2-amino-3-chloro-5-trifluoromethylpyridine: syntheses,structures, and magnetic properties of [(TMCAPH)2CuBr4] and [(TMCAPH)2CuCl4]

The reaction of CuX₂ (X = Br or Cl) with 2-amino-3-chloro-5-trifluoromethylpyridine in aqueous acids (HX; X = Br or Cl) yields bis(2-amino-3-chloro-5-trifluoromethylpyridinium)tetrabromocuprate(II) (1) and bis(2-amino-3-chloro-5-trifluoromethylpyridinium)tetrachlorocuprate(II) (2). These compounds have been characterized by IR, powder X-ray diffraction (XRD), single crystal XRD, combustion analysis, and temperature-dependent magnetic susceptibility. Compound 1 crystallizes in the monoclinic space group P2₁/c with three ions in the asymmetric unit, whereas 2 crystallizes in the triclinic space group P 1, and the asymmetric unit contains 18 ionic moieties. Both compounds exhibit antiferromagnetic exchange via the double halide exchange pathway and singlet ground states, with stronger exchange observed for 1. Both compounds exhibit multiple potential magnetic exchange pathways, but fitting of the data to available analytical models suggests that the magnetic exchange constants 2J/k _B are ～50 K in 1 and ～6 K in 2, respectively.     

Transition metal salts of quinoline: synthesis,structure and magnetic behavior of (QuinH)2[MX4]·2H2O [Quin = quinoline; M = Mn,Co, Cu,Zn], (QuinH)2[MnBr2(H2O)2](Br)2 and (QuinH)[Cu(Quin)Br3]

Abstract

A family of compounds of general formula (QuinH)₂MX₄·2H₂O has been prepared and characterized [Quin?=?quinoline; M, X?=?Co,Cl (1); M, X?=?Co,Br (2); M, X?=?Zn,Br (3); M, X?=?Mn,Cl (4)]. The complexes crystallize in the monoclinic space group C2/c as well-isolated layers containing the MX₄^?2 anions and water molecules, separated by the quinolinium cations. The bromide analogue of 4, compound 5 (QuinH)₂[MnBr₂(H₂O)₂](Br)₂, also crystallizes in the C2/c space group, but comprises a co-crystal of manganese bromide dihydrate and quinolinium bromide. The temperature dependent magnetic properties of the complexes are described, along with the tetrachlorocuprate analogue (7). All compounds show weak antiferromagnetic interactions (J/k_B?～?0.06–1.4 K) and good one- or two-dimensional isolation. In addition, the crystal structure of the mixed quinoline/quinolinium complex (QuinH)[Cu(Quin)Br₃] (triclinic, P-1) is reported.     

Cyclische Diazastannylene. XXXII. Zur Synthese und Reaktivität difunktionalisierter Cyclosilagermadiazane—Bildung von Digermanen

Cyclic Diazastannylenes. XXXII. On the Synthesis and Reactivity of Difunctional Cyclosilagermadiazanes—Formation of Digermanes The cyclic bisaminostannylene Me₂Si(t-BuN)₂Sn 1 reacts with tetrahalides of germanium GeX₄(X = Cl, Br, I) forming the bisaminodihalogengermanes 2a, 2b and 2c. The halogen atoms of the compounds 2 may be substituted by alkyl-, amino- and pseudohalide groups: Me₂Si(t-BuN)₂GeXY (X = Y = N₃ 3 ; X = Br, Y = Me 4 , Y = t-Bu 6 , Y = N(SiMe₃)₂ 8a , Y = NEt₂ 9 ; X = Me, Y = N₃ 5a , Y = CN 5b ; X = N₃, Y = t-Bu 7 , Y = N(SiMe₃)₂ 10 ; X = I, Y = N(SiMe₃)₂ 8b ). Reduction of the compounds 2b and 4 with sodium naphthalide generates the digermanes (Me₂Si(t-BuN)₂GeR)₂ (with R = Br 11 , R = Me 12 ) Compound 8b crystallizes in the monoclinic space group P2₁/c with Z = 8 and lattice constants a = 16.205(8), b = 19.854(9), c = 17.537(9) Å, β = 107.50(9)°. Compound 11 crystallizes in the triclinic space group P1 with Z = 2 and lattice constants a = 8.921(4), b = 11.091(5), c = 17.590(8) Å, α = 80.5(1), β = 89.2(1), γ = 71.4(1)°.     

A 2D coordination polymer with 4*82 topology constructed from a new T -shaped ligand: synthesis,crystal structure and photoluminescence

A cadmium(II) coordination polymer [CdL(H₂O)] (1) (H₂L?=?3,3-bis(carboxymethyl)imidazo[1,2-a]pyridin-2-one) was synthesized under hydrothermal conditions and characterized by X-ray structure analysis. Compound 1 crystallizes in the monoclinic space group P2₁/n with a?=?11.945(2)?Å, b?=?8.0865(16)?Å, c?=?13.114(3)?Å, β?=?91.36(3)°, Z?=?4, and represents a 2D network with the 4*8² topology constructed from combination of metal centers with a T-shaped geometry and ligands with T-shaped structure simultaneously. Compound 1 also exhibits strong photoluminescence at room temperature.     

Syntheses,characterizations, and antimicrobial activities of binuclear ruthenium(III) complexes containing 2-substituted benzimidazole derivatives

Binuclear ruthenium(III) complexes [RuX₃L]₂?·?nH₂O (X?=?Cl, L?=?L¹, L², L³; n?=?1, L⁴ and L⁵, X?=?Br; L?=?L³), [RuX₃L_1.5]₂?·?nH₂O (X?=?Br, L?=?L¹; n?=?0, L⁴; n?=?6 and L⁵; n?=?10), and [RuX₃L₂]₂ (X?=?Br, L?=?L²) have been isolated by treatment of hydrated RuX₃ (X?=?Cl/Br) in acetone with 2-(2′-aminophenylbenzimidazole) (L¹), 2-(3′-aminophenylbenzimidazole) (L²), 2-[(3′-N-salicylidinephenyl)benzimidazole] (L³), 2-(3′-pyridylbenzimidazole) (L⁴), and 2-(4′-pyridylbenzimidazole) (L⁵) in acetone. The complexes were characterized by elemental analysis, conductivity and magnetic susceptibility measurements, IR, electronic, EPR, and mass spectral studies. The complexes were dimeric; based on analytical and spectral studies, an octahedral geometry was proposed for the complexes. The synthesized complexes were screened against Gram-positive and Gram-negative bacteria and fungi.     

Binuclear cyclopalladated compounds with antitubercular activity: synthesis and characterization of [{Pd(C2,N-dmba)(X)}2(μ-bpp)] (X = Cl,Br, NCO,N3; bpp = 1,3-bis(4-pyridyl)propane)

Reactions between [Pd(C²,N-dmba)(μ-X)]₂ (Hdmba?=?N,N-dimethylbenzylamine; X?=?Cl, Br, NCO, N₃) and 1,3-bis(4-pyridyl)propane (bpp) in 1?:?1 molar ratio at room temperature resulted in the binuclear compounds [{Pd(C²,N-dmba)(X)}₂(μ-bpp)] (X?=?Cl (1), Br (2), NCO (3), N₃ (4)), which were characterized by elemental analyses, infrared (IR), ¹H- and ¹³C{¹H}-NMR spectroscopies, and thermogravimetric analysis. The IR and NMR data of 1–4 were consistent with the presence of bridging bpp. The thermal stability order of the complexes was 4?>?3?>?2?>?1. Compounds 1–4 and bpp were tested against Mycobacterium tuberculosis and their MIC values were determined.     

Strukturen von neuen Bis(pentafluorophenyl)halogenomercuraten [{Hg(C6F5)2}3(μ‐X)]— (X = Cl,Br, I)

Structures of New Bis(pentafluorophenyl)halogeno Mercurates [{Hg(C₆F₅)₂}₃(μ‐X)]^— (X = Cl, Br, I) From the reactions of [PNP]Cl or [PPh₄]Y (Y = Br, I) with Hg(C₆F₅)₂ crystals of the composition [Cat][{Hg(C₆F₅)₂}₃X] (Cat = PNP, X = Cl ( 1 ); Cat = PPh₄, X = Br ( 2 ), I ( 3 )) are formed. 1 crystallizes in the triclinic space group P1¯, 2 and 3 crystallize isotypically in the monoclinic space group C2/c. In the crystals the halide anions are surrounded by three Hg(C₆F₅)₂ molecules. The reaction of [PPh₄]Br with Hg(C₆F₅)₂ under slightly changed conditions gives the compound [PPh₄]₂[{Hg(C₆F₅)₂}₃(μ‐Br)][{Hg(C₆F₅)₂}₂(μ‐Br)] ( 4 ).     

Catalytic activity of some new copper(II) azo-complexes

Copper(II) complexes [Cu(L)₂]?·?nH₂O, where L is 3-(p-X-)-4-hydroxy-l,2-naphthoquinone (for L1, X?=?H; L2, X?=?CH₃; L3, X?=?Cl; L4, X?=?Br; and L5, X?=?NO₂), have been synthesized and characterized by analytical, electrochemical, spectroscopic (IR, UV-Vis, ESR, and ¹H NMR), and magnetic methods. From the data obtained, square-planar geometry has been assigned for all the complexes. [CuL1]?·?H₂O exhibits catalytic activity for oxidation of benzyl alcohol, piperonyl alcohol, and cinnamyl alcohol into their respective aldehydes in the presence of H₂O₂ as co-oxidant and in CH₃CN and H₂O as solvents at room temperature.     

Synthesis,characterization, crystal structure,and electrochemical properties of three copper(II) complexes with 3,5-dihalosalicylaldehyde Schiff bases derived from amantadine

Abstract

Complexes 1-3, C₃₄H₃₆X₄CuN₂O₂ (X?=?Cl, Br, I), were synthesized with copper chloride dihydrate and three new Schiff base ligands derived from amantadine and 3,5-dihalosalicylaldehydes. They were characterized by IR, UV–VIS, elemental analysis, molar conductance, and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis reveals that 1 and 2 crystallize in the triclinic system, Pī space group. Each asymmetric unit consists of one copper(II) ion, two corresponding deprotonated Schiff base ligands and one lattice dichloromethane molecule. 3 crystallizes in the monoclinic system, P2₁/n space group. Each asymmetric unit consists of one copper(II) ion and two deprotonated iodo- Schiff base ligands. The tetra-coordination of the central copper(II) ion in 1-3 is constructed by two nitrogen atoms and two oxygen atoms from the corresponding Schiff base ligands, forming a distorted tetrahedral geometry. Electrochemical properties of the complexes were determined by cyclic voltammetry.

     

Synthesis,X-ray characterization,and in vitro biological approach of dimeric and polymeric mercury(II) complexes with α-keto stabilized sulfur ylide

Abstract

Reaction of α-keto stabilized sulfur ylide (Me)₂SCHC(O)C₆H₄-p-CN (Y) with HgX₂ (X?=?Cl, Br, and I) led to the formation of new dinuclear products of the type [HgX₂(Y)]₂ (X?=?Cl (1), Br (2), and I (3)). Furthermore, the reaction of the corresponding sulfur ylide (Y) with Hg(NO₃)₂·H₂O in equimolar ratio, using methanol as a solvent, was shown to produce the polynuclear complex [(Y)Hg(NO₃)₂]_n (4). The obtained compounds were characterized using elemental analysis, IR, ¹H and ¹³C NMR techniques. The structures of compounds Y and 1 were characterized by single-crystal X-ray diffraction (XRD) analysis. Also, in order to confirm the crystalline nature of complexes 1–3, powder XRD pattern was used. Likewise, the antioxidant property of the complexes was examined by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging which revealed the strong-to-moderate radical scavenging ability (IC₅₀; 0.163?±?0.004 to 0.936?±?0.012?mg·mL^?1) of the synthesized compounds. Further, results from this study indicated that the compounds possess moderate antibacterial activity.     

Coinage (Cu,Ag) metal derivatives of salicylaldehyde N-ethylthiosemicarbazone: synthesis,spectroscopy, and structures

Reactions of copper(I) halides with triphenyl phosphine in acetonitrile followed by the addition of salicylaldehyde N-ethylthiosemicarbazone {(2-OH–C₆H₄)(H)C²=N³–N²H–C¹(=S)N¹HEt, H₂stsc-NEt} in chloroform in 1?:?2?:?1 (Cl) or 1?:?1?:?1 (Br, I) molar ratios yield mononuclear, [CuCl(η ¹-S-H₂stsc-NHEt)(PPh₃)₂] (1) and sulfur-bridged dinuclear, [Cu₂X₂(μ-S-H₂stsc-NEt)₂(PPh₃)₂] (X?=?Br, 4; I, 5) complexes. Similarly, reaction of silver halides (Cl, Br) with H₂stsc-NEt in acetonitrile followed by the addition of PPh₃ to the solid that formed (1?:?1?:?2 molar ratio), yielding mononuclear complexes, [AgX(η ¹-S-H₂stsc-NHEt)(PPh₃)₂] (Cl, 2; Br, 3). All these complexes are characterized with analytical data, IR, and NMR spectroscopy and single-crystal X-ray crystallography. The ligand favored η ¹-S bonding in 1, 2, and 3, and μ-S bonding in 4 and 5. Cu?···?Cu contacts were 3.063?Å. The complexes form 1-D or 2-D H-bonded networks, entrapping solvent in some cases.     

α-Keggin tungstogermanate-supported transition metal complexes: hydrothermal synthesis,characterization, and magnetism of Cu2(phen)4(GeW12O40) and [Ni2(bpy)4(H2O)2(GeW12O40)]⋅2H2O

Two new α-Keggin polyoxometalates, [Cu₂(phen)₄(GeW₁₂O₄₀)] (1) and [Ni₂(bpy)₄(H₂O)₂(GeW₁₂O₄₀)]·2H₂O (2) (phen?=?1,10-phenanthroline, bpy?=?2,2′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, single-crystal X-ray diffraction, and magnetic properties. Compound 1 crystallizes in the monoclinic system, space group P2(1)/c, and 1 is assembled into two-dimensional (2-D) layers parallel to (1?0?1) based on the adjacent phen π···π stacking interactions (3.788(8)?Å). Variable temperature magnetic measurements show ferromagnetic behavior from 300 to 2?K. Compound 2 crystallizes in the triclinic system, space group P-1, and 2 is assembled into 2-D layers parallel to (1?0?1) based on the adjacent bpy π···π stacking interactions (3.07?Å). Variable temperature magnetic measurements show a weak ferromagnetic behavior from 300 to 26?K followed by antiferromagnetic behavior below 26?K.     

Syntheses,characterization, and structures of three ruthenium complexes containing two monodentate dppm ligands

Three cis-Ru(dppm)₂XY complexes (XY?=?C₂O₄, 1; X?=?Cl, Y?=?N₃, 2; X?=?Y?=?N₃, 3) were prepared by reactions of cis-Ru(dppm)₂Cl₂ with (NH₄)₂C₂O₄, a mixture of NaN₃ and NaPF₆, and only NaN₃, respectively, while 3 could also be obtained from further reaction of 2 with NaN₃ undergoing a facile chloride abstraction. All complexes have been characterized by IR, NMR, UV–vis, and luminescence spectroscopic analyses as well as X-ray diffraction studies. Of these structures, 1 shows oxalate coordinates to Ru as a chelating ligand, while 2 displays Ru and azide linear, and 3 gives two azide groups cis to each other, which are different from two substituting ligands commonly lying in trans positions in Ru(P–P)₂ complexes by using cis-Ru(dppm)₂Cl₂ as a precursor.     

Synthesis and Characterization of Alkyltris(2-pyridyl)phosphonium Salts

Alkytris(2-pyridyl)phosphonium salts [(2-Py) ₃ PR]X 1 [1a, R = Et, X = Br; 1b, R = Pr, X = Br; 1c, R = Bu, X = Br; 1d, R = CH₂Ph, X = Br; 1e, R = CH ₂ Ph, X = Cl] were synthesised from (2-Py) ₃ P and an excess of RCl. 1c and 1e were found to rapidly decompose in hot acetone to 2,2′-bipyridinium(+1) bromide 2 and (2-Py)P(O)(CH ₂ Ph)C(OH)Me ₂ 3, respectively. A reaction mechanism for both products is proposed. All compounds were fully characterized, including X-ray crystallography for 1a and 3 with 1a being the first representative of this class of compounds characterized by this technique.     

Ab Initio Calculations Show How 31PNMR Chemical Shifts in PXYZ Phosphines Correlate with Substituent Electronegativity

Abstract

Letcher and Van Wazers suggestion[1] that the ³¹P NMR chemical shifts of phosphines might be related to the substituent electronegativity, EN(X)[2], has not been verified subsequently by the available experimental data[3,4]. We now have explored this relationship systematically by means of reliable[5] ab initio magnetic property calculations[6] on a comprehensive set of molecules: PXY2 (Y= H, F, CH₃, Cl) and PXYZ (Y= H, Cl and Z= F) with X= H, CH₃, NH₂, OH, F, SiH₃, PH₂, SH, Cl.     

Supramolecular structures of CdX2-containing coordination compounds constructed by C–H ··· X synthons

Three CdX₂-containing (X = Cl, Br) compounds [CdBr₂(Him)₂] _n (Him = imidazole) (1), [CdCl₂(2,2′-bipy)] _n (2,2′-bipy = 2,2′-bipyridine) (2), and [CdCl₂(phen)] (phen = phenanthroline) (3) have been synthesized through hydrothermal technique. Compound 1 adopts 1-D coordination chain, which is connected to form a 3-D supramolecular network by inter-chain N–H ··· Br and C–H ··· Br hydrogen bonds. Compound 2 also adopts 1-D coordination chain, which is connected to form 3-D supramolecular network by intra- and inter-chain C–H ··· Cl hydrogen bonds; 3 is discrete, linked to form 2-D supramolecular sheets by intra- and inter-molecular C–H ··· Cl hydrogen bonds. The different volume and coordination ability of organic ligands result in the different coordination structure and supramolecular synthons. All these compounds exhibit strong fluorescence emissions at room temperature.     

Structural effects of lone-pair electrons: a novel three-dimensional,open-framework metal selenite constructed from {CoSeO3}n double helical chains linked via ethylenediamine pillars

A novel three-dimensional, open-framework selenite [H₂N(CH₂)₂NH₂]_0.5·CoSeO₃ (1) has been hydrothermally synthesized and characterized by elemental analyses, IR spectrum, XPS spectrum, TG analysis and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system, space group P2₁/n, with a?=?6.6018(14)?Å, b?=?9.2559(19)?Å, c?=?7.9097(16)?Å, β?=?113.56(3)°, V?=?443.02(16)?ų, and Z?=?4. Compound 1 exhibits an interesting three-dimensional open-framework structure constructed from unique {CoSeO₃}_n layers aggregated from double helical chains pillared by en ligands. Furthermore, the open framework of 1 possesses three types of one-dimensional channels, in which the triangular channel is particularly rare in covalently bonded microporous materials.