Syntheses,Crystal Structures and Fluorescence Properties of Zn(II) Complexes with Pyrazolone Derivatives

Abstract   N-(1,3-Diphenyl-4-benzal-5-pyrazolone)-salicylidene hydrazone(H₂L ¹ ) and its zinc complex Zn(HL ¹ )₂ · 2CH₃OH (1) have been synthesized and characterized by elemental analyses, IR spectra, thermal analyses and single-crystal X-ray diffraction studies. The X-ray diffraction analyses of the complex Zn(HL ¹ )₂ · 2CH₃OH (1) and the known compound Zn₄(L ² )₄ (2) (H₂L ²  = N-(1,3-diphenyl-4-phenylethylene-5-pyrazolone)-salicylidene hydrazone) show that different acyl groups in position 4 of pyrazolones may lead to the different coordination mode of the ligands and distinctive structures of the same central metal Zn(II) complexes, of which 1 is a mononuclear complex while 2 is a tetranuclear complex. Meanwhile, two Zn(II) complexes have different thermal stabilities and fluorescence properties. Graphical Abstract        

Self-Assembly of Two Isomorphous Thiocyanate Complexes of Co(II) and Ni(II) with 3-Hydroxypicolinamide

Abstract  

The synthesis, thermal and spectral characterization, and crystal structure of isomorphous thiocyanate cobalt(II) and nickel(II) complexes with 3-hydroxypicolinamide (3-OHpia), [M(C₆H₆N₂O₂)₂(NCS)₂]·2H₂O, are reported. The metal(II) ions are chelated by two cis-oriented 3-OHpia and two thiocyanate ligands in distorted octahedral geometry. The distortion within the coordination sphere is mainly imposed by formation of the chelate rings. The compounds crystallize in monoclinic space group P2/c with two symmetrically independent molecules and a = 14.4945(2) ?, b = 8.5906(1) ?, c = 16.3865(3) ?, β = 105.987(2)°, Z = 4 (1) and a = 14.4927(5) ?, b = 8.5912(3) ?, c = 16.2712(6) ?, β = 105.740(4)°, Z = 4 (2). Commonly observed supramolecular amide synthons are not robust enough to accommodate thiocyanate ions and H₂O molecules. But instead, neutral complexes are linked through hydrogen bonds leading to two different hydrogen bonding ribbon motifs involving amide moieties and H₂O molecules [C(8)R ₂²(12) along c axis] and amide moieties and thiocyanate ions [C(8)R ₂²(16) along b axis] for symmetrically related molecules labelled as 1 [Co1 (1) and Ni1 (2)] and 2 [Co2 (1) and Ni2 (2)], respectively.     

Synthesis, Crystal Structures and Properties of Two Copper (II) Complexes with Pyridazine Derivative Ligand

Abstract  Two new complexes, [Cu(L)₂(CH₃OH)] · (ClO₄)₂ (1) and [Cu(L)₂(H₂O)] · (NO₃)₂ (2), have been synthesized and their crystal structures have been determined by X-ray analysis, where L = 3-(3,5-bimethylpyrazole-yl)-6-chloro-pyridazine]. The complex 1 crystallizes in the monoclinic, space group C2/c, and the coordination configuration of copper (II) is better described as trigonal pyramidal geometry with four N atoms from L and one O_methanol^. The coordination configuration of 2 is quite similar to that of 1 except O_water instead of O_methanol^. The intermolecular hydrogen bonds link the repeat units and extend the molecules to multinuclear structures in both compounds. The spectral properties of the title compounds have been studied and discussed. Furthermore, the antibacterial activities of the title compounds have been detected, the results indicate that the ligands and two copper(II) complexes exhibit certain fungicidal activities again several bacteria. Index Abstract  Two new complexes, [Cu(L)2(CH3OH)]·(ClO4)2 (1) and [Cu(L)2(H2O)]·(NO3)2 (2), have been synthesized and their crystal structures have been determined by X-ray analysis, where L= 3-(3,5-bimethylpyrazole-yl)-6-chloro-pyridazine. The intermolecular hydrogen bonds extend the molecules to multinuclear structures in both compounds.      

Syntheses, Characterizations and Crystal Structures of Two Copper Coordination Polymers Both Having Cu2Cl2 Bridging Subunit [CuI(bipy)1/2Cl]n(1) and {[(CuII)4(phen)4(SSA)2Cl2](H2O)2(DMF)2}n(2)

Abstract  

Two copper coordination polymers [Cu^I(bipy)_1/2Cl] _n (1) and {[(Cu^II)₄(phen)₄(SSA)₂Cl₂] (H₂O)₂(DMF)₂} _n (2)(bipy = 4,4′-bipyridine, phen = 1,10-phenanthroline, H₃SSA = 5-sulfosalicylic acid, DMF = N,N-dimethylformamide) have been prepared and characterized by X-ray diffraction, elemental analysis, IR spectrum and 2 was also studied by cyclic voltammetric method. X-ray analysis indicates that both of them have Cu₂Cl₂ bridging subunit. Complex 1 is a two dimensional network structure. While 2 shows a one dimensional zigzag chain. Electrochemistry studies reveal that complex 2 undergo a quasi reversible one-electron metal-centered redox process at E _1/2 = +0.062 V.     

Synthesis and Crystal Structure of a New Cobalt(II) Complex: Bis(pyridine)bis(4,4,4-trifluoro-1-(6-methoxynaphthalen-2-yl)butane-1,3-dione) Cobalt(II)

Abstract  

A new Co(II) complex 2 with ligand 4,4,4-trifluoro-1-(6-methoxynaphthalen-2-yl) butane-1,3-dione 1 and pyridine are prepared and crystallized from an acetone solution. The obtained red and transparent crystal conforms to the empirical formula of Co(C₁₅H₁₀O₃F₃)₂·(C₅H₅N)₂. It crystallizes in monoclinic, space group C2/c with a = 23.3152(14), b = 12.0225(7), c = 15.3950(10) ?, β = 124.1360(10)°, V = 3571.8(4) ?³, Z = 4, C₄₀H₃₀CoF₆N₂O₆, Mr = 807.59, F(000) = 1652, Dc = 1.502 g/cm³, μ = 0.564 mm⁻¹, the final R = 0.0466 and wR = 0.1043 for 3901 observed reflections with I > 2σ(I). X-ray structural analysis revealed that the Co(II) atom is coordinated by two oxygen atoms of 1,3-dione ligands 1 and two nitrogen atoms of pyridines, forming a distorted octahedron coordination geometry.     

Syntheses,Structures and Luminescent Properties of Zinc(II) and Cadmium(II) Complexes With the Ditopic Ligand 1,3-Bis(imidazol-1-ylmethyl)benzene

Abstract  

Three new complexes, namely [Zn(mbix)(SO₄)]·CH₃OH (1), Cd(mbix)₂(NO₃)₂ (2) and [Cd(mbix)₂(H₂O)₂]·(NO₃)₂ (3), have been obtained by reactions of flexible bidentate ligand 1,3-bis(imidazol-1-ylmethyl)benzene (mbix) with corresponding zinc(II) and cadmium(II) salts. The structures of these complexes have been determined by the X-ray single crystal diffraction analysis. Complex 1 features a 2D wavy network with (4,4) topology. Complex 2 has a 2D grid network with left- and right-handed helical chains, while complex 3 exhibits twofold parallel interpenetration structure. The differences of three complexes demonstrate that the coordination geometry of metal ions and the ratio of reactants have a great impact on the structure of the supramolecular architectures. The luminescent properties of three complexes are also investigated.     

Hydrogen-bonded Three-dimensional Supramolecular Network Constructed by Dinuclear Ni(II) Macrocyclic Complex and 1,2,4,5-Benzenetetracarboxylate

Abstract  

A new coordination polymer [Ni₂(L)(H₂btec)]_n, (1) was obtained from the reaction of NiSO₄·6H₂O, macrocyclic ligand 3,6,9,17,20,23-hexaaza-29,30-dihydroxy-13,27-di-tert-butyl-tricyclo[23,3,1,1^11,15]triaconta-1(28),11,13,15(30),25,26-hexaene (H₂L), and 1,2,4,5-benzenetetracarboxylic acid (H₄btec) in methanol. Its structure was determined by X-ray diffraction analysis. The crystal is monoclinic C2/c space group with cell parameters a = 20.4923(3) ?, b = 14.2389(3) ?, c = 14.5130(2) ?, β = 97.441(2)°, V = 4199.05(12) ?³, and Z = 8. The X-ray analysis shows that each Ni (II) cation is six-coordinated by an O₃N₃ donor set. The macrocyclic complex [Ni₂L] ²⁺ are bridged by H₂btec²⁻ anions to form 1D chains, which are further joined via N–H···O hydrogen bonds to yield a 3D supramolecular structure. Thermogravimetric analysis (TGA) for the complex is discussed.     

Syntheses,Crystal Structures and Physical Properties of Cd(II) and Mn(II) Complexes with <Emphasis Type="Italic">Trans</Emphasis>-1,2-di(4-pyrindyl)ethylene and <Emphasis Type="Italic">P</Emphasis>-(carboxyl-methyloxy)-benzenecarboxylic Acid

Abstract  

Two complexes [Cd₂(dpe)₃(H₂O)₈]·(dpe)·(hssal)₂·(H₂O)₂ 1, [Mn(dpe)₂(Hpcmb)₂·(H₂O)₂] 2, (dpe = trans-1,2-di(4-pyrindyl)ethylene; H₂hssal = sulphosalicylic acid; H₂pcmb = p-(carboxyl-methyloxy)-benzenecarboxylic acid) has been prepared, and was characterized by elemental analysis, FT-IR and single-crystal X-ray diffraction. Structure indicates in complex 1 that Cd(II) is a distorted octahedral coordination geometry. The hssal²⁻ anions are localized between 2-D sheets {[Cd(dpe)₂(H₂O)₄]²⁺(dpe)}n and {{[Cd(dpe)₂(H₂O)₄]²⁺}n as count anions and bridge to further connect these 2-D sheets through hydrogen bond O–H···O to form 3-D structure. The complex 2 is a single molecule structure. In 2, Each Mn(II) atom is six-coordinated with a distorted octahedral coordination geometry. The single molecule units are extended into three-dimensional structure via π–π, hydrogen bonding interactions. The thermogravimetric behavior and luminescent property of complex 1 were investigated.     

Synthesis, Spectroscopic and Thermal Studies of Zinc(II) Complexes with the Symmetrical Bidentate Schiff-Base Ligand (2,3-MeO-ba)2en: Crystal Structure of Zn((2,3-MeO-ba)2en)I2

Abstract  

Two zinc(II) complexes [ZnI₂((2,3-MeO-ba)₂en)] (1) and [ZnCl₂((2,3-MeO-ba)₂en)] (2), with the symmetrical bidentate Schiff-base ligand (2,3-MeO-ba)₂en [N,N′-bis(2,3-dimethoxybenzylidene)-1,2-diaminoethane] have been synthesized and characterized by elemental analyses (CHN), FT-IR and ¹H-NMR spectroscopy. The thermal behaviors of these complexes were studied using thermogravimetry in order to evaluate their thermal stability and thermal decomposition pathways. The crystal structure of [ZnI₂((2,3-MeO-ba)₂en)] (1) was determined from single-crystal X-ray diffraction. The coordination polyhedron about the zinc(II) center in the complex 1 is best described as a distorted tetrahedron.     

Synthesis,Characterisation and Magnetic Properties of a One-Dimensional Iron(II) Coordination Polymer

Abstract  

A new iron(II) coordination polymer, [FeCl₂(NC₇H₉)₂(N₂C₁₂H₁₂)], has been synthesized under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction. This material crystallizes in the monoclinic space group C2/c, with a = 11.2850(6), b = 13.8925(7), c = 17.0988(9) ? and β = 94.300(3)o (Z = 4). The crystal structure consists of neutral zig-zag chains, in which the iron(II) ions are octahedrally coordinated. The infinite polymer chains are packed into a three-dimensional structure through C–H···Cl interactions. Magnetic susceptibility measurements reveal the existence of weak antiferromagnetic interactions between the iron(II) ions. The effective magnetic moment, μ _eff = 5.33 μ _B , is consistent with a high-spin iron(II) configuration.     

Synthesis and Crystal Structures of Anionic Gallium(II) and Gallium(III) Heterocyclic Compounds Derived from a Gallium(I) N-Heterocyclic Carbene Analogue

Abstract  

The addition of the N–H bond of the formamidine, ArN(H)C=NAr (Ar = C₆H₃Pr₂ⁱ-2,6), to the gallium(I) center of [K(tmeda)][:Ga(Ar-DAB)] (Ar-DAB={(Ar)NC(H)}₂) yields K[(Ar-DAB)Ga^III(H){N(Ar)C=NAr}] 1. The crystal structure of this and two other related anionic compounds, [K(18-crown-6)][(Ar-DAB)Ga^III{N(H)N=Fl}{(H)Fl}] (Fl = fluorendiyl) 2 and [K(OEt₂)₃][(Ar-DAB)Ga^II(CH₂Ph)Ga^II(Ar-DAB)] 3, have been determined. The cell parameters of the compounds are 1: P2₁/c, a = 20.2350(9), b = 14.1760(7), c = 19.6441(10), β = 111.307(1); 2: P2₁/c, a = 13.115(3), b = 21.799(4), c = 22.646(5), β = 90.20(3); 3: P2₁/n, a = 16.783(3), b = 21.635(4), c = 19.814(4), β = 92.34(3). The crystal structures of all complexes exhibit distorted tetrahedral gallium centers, and interactions between anion aryl substituents and the potassium cations.     

Two Different Compounds Formed from Copper(II) tetrafluoridoborate and [1,2,4]triazolo[1,5-a]pyrimidine. Synthesis,Spectroscopy and Single-Crystal Structures

Abstract  

Two coordination compounds copper(II) with tetrafluoridoborate as the anion and [1,2,4]triazolo[1,5-a]pyrimidine (abbreviated as tp) as the ligand are presented, together with their crystal structure and spectroscopic properties. A light blue compound [Cu(tp)₄(H₂O)₂](BF₄)₂(CH₃OH) (1) with a tetragonal chromophore and a dark blue compound [Cu(tp)₅](BF₄)₂(CH₃OH) (2) are formed from the same batch. Compound (2) has a quite unusual geometry for Cu(II) with just 5 tp ligands, homoleptically coordinated to the metal ion. Both compounds show interesting hydrogen-bond interactions in the solid state, where coordinated water is intramolecularly bound to non-coordinated N atoms of tp (in 1), and methanol is attached to the anion (in 2).     

Red and Blue Compounds Formed from Copper(II) Bromide and the Ligand 7-Isobutyl-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidine: Synthesis, Spectroscopy and Single-Crystal Structures

Abstract  

Two newly synthesized coordination compounds copper(II) bromide with the ligand 7-isobutyl-5-methyl[1,2,4]triazolo[1,5-a]pyrimidine (abbreviated as ibmtp) are presented, together with their 3D crystal structure and spectroscopic and magnetic properties. The compounds are CuBr₂(ibmtp)₂ (1) (red crystals) and [CuBr(ibmtp)₄]Br(H₂O)₃ (2) (blue crystals). In (1) the Cu(ii) ion is present in a distorted tetrahedral environment, while in (2) the Cu(ii) ion has a square pyramidal geometry. These crystal structures are also the first ones reported with the ligand ibmtp.     

Crystal Structure and Magnetic Properties of a Novel Octa-coordinated Manganese(II) Complex

Abstract  The self-assembly and structural characterization of the new manganese(II) [MnL ₂](ClO₄)₂(CH₃OH)_0.5 (1) complex has been achieved. The crystallographic data for the complex 1: Orthorhombic Pbca , a = 16.287(2) ?, b = 21.293(2)?, c = 32.718(3) ?, V = 11,347(2) ?³, Z = 8. The two polydentate ligands strand intertwined each other and around the manganese(II) ions forming a mononuclear complex. The Mn(II) ion is eight-coordinated with the eight donor nitrogen atoms of two ligands to form a distorted square antiprismatic coordination geometry. The magnetic properties investigation indicates that there is a weak antiferromagnetic exchange coupling between the Mn(II) ions of the complex. Index Abstract  An octa-coordinated Mn(II) complex which exhibits a distorted square antiprismatic coordination geometry has been achieved by using a bisbidentate Schiff-base ligand.      

Nickel(II) and cobalt(II) nitrate and chloride networks with 2-aminopyrimidine

The coordination chemistry of 2-aminopyrimidine (PymNH₂) with nickel(II) and cobalt(II) nitrate and chloride is reported, including seven new X-ray crystal structures. Two [Ni(NO₃)₂(PymNH₂)₂(OH₂)] isomers were found (A: C2/c, a=13.3006(5), b=7.9727(3), c=28.5453(11), β=101.758(2), V=2963.48(19), Z=8 and B·1/2 acetone: P2₁/c, a=7.66060(10), b=10.6792(2), c=20.6790(3), β=100.2970(10), 1664.48(5), Z=4). In both cases one nitrate is monodentate and the other is chelating and the PymNH₂ ligands coordinate through ring nitrogen atoms. Hydrogen bonding results in double sheet structure for isomer A, and a three dimensional channeled network for isomer B. [Co(NO₃)₂(PymNH₂)₂(OH₂)] (C2/c, a=13.3507(2), b=7.99520(10), c=28.6734(3), β=102.3540(10), V=2989.77(7), Z=8) is isostructural to Ni isomer A. [CoCl₂(PymNH₂)] (Cmcm, a=3.6139(2), b=14.3170(7), c=12.9986(7), V=672.55(6), Z=4) is a sheet coordination network, consisting of corner-sharing chains of Co₂(μ-Cl)₂ bridged by PymNH₂ through ring nitrogen atoms; [CoCl₂(PymNH₂)₂] (C2/c, a=11.2774(6), b=6.5947(4), c=16.5687(9), β=92.269(3), V=1231.27(12), Z=4) is a tetrahedral molecule knit into a ribbon structures through pairs of hydrogen bonds. Isostructural trans-[NiCl₂(PymNH₂)₄] (C2/c, a=7.67760(10), b=18.7224(3), c=15.0418(2), β=99.6740(10), V=2131.41(5), Z=4) and trans-[CoCl₂(PymNH₂)₄] (C2/c, a=7.69120(10), b=18.5957(2), c=15.1091(2), β=99.5280(10), V=2131.14(5), Z=4) are simple octahedral molecules, with hydrogen-bonding producing sheet structures.     

Synthesis,Crystal Structure and Characterizations of New 3,4,7,8-Tetrachloro-1,10-Phenanthroline Zn(II) Complex

Abstract  

A novel 3,4,7,8-tetrachloro-1,10-phenanthroline (Cl₄phen) Zn(II) complex has been synthesized. The complex, [Zn(Cl₄phen)₂(H₂O)₂](NO₃)₂·CH₃CH₂OH (1), has been identified and characterized by single crystal X-ray diffraction, elemental analysis, FT-IR, thermogravimetric analysis and photoluminescence studies. Single crystal X-ray diffraction analysis reveals that complex (1) belongs to the monoclinic system, space group P2(1)/c, a = 10.061(2) Å, b = 18.924(4) Å, c = 18.189(4) Å, β = 100.94(3)°, and Z = 4. Complex (1) consists of cationic species [Zn(Cl₄phen)₂(H₂O)₂]²⁺, NO₃ ⁻ and CH₃CH₂OH. The zinc atom displays a distorted cis-N₄O₂ octahedral geometry. Via extended Zn–O–H···O–N–O···H–O–Zn bridge, every mononuclear unit is linked with other ones to form one-dimensional (1D) infinite chain of hydrogen bond system. Three-dimensional (3D) polymeric network arrangement was built via weak C–H···O and π-stacking interactions between Cl₄phen moieties. A solvent-dependency effect of complex (1) was observed in spectroscopic properties.     

A Unique Example of a Co-crystal of [Co(AMTTO)2(H2O)2](NO3)2 and [Co(AMTTO)2(CH3CN)2](NO3)2 (AMTTO = 4-amino-5-methyl-1,2,4-triazol-3(2H)-thione)

A co-crystal of cobalt(II) complexes, Co(AMTTO)₂(CH₃CN)₂]²⁺(NO₃)₂. [Co(AMTTO)₂(H₂O)₂]²⁺(NO₃)₂, compound (1) was isolated from the reaction of Co(NO₃)₂?6H₂O and 4-amino-3-mercapto-6-methyl-5-oxo-1,2,4-triazine (AMTTO) in acetonitrile as solvent. Isolated crystals were characterized by elemental analyses, IR spectroscopy as well as X-ray diffraction studies. Crystal data for 1 at 95 K revealed a monoclinic space group P2₁/n, a?=?11.7903(5), b?=?12.1279(5), c?=?14.1443(6) Å, β?=?99.244(4)°, Z?=?2, R₁?=?0.0339. Compound 1 consists of two co-crystallized Co(II) complexes [Co(AMTTO)₂(CH₃CN)₂]²⁺ and [Co(AMTTO)₂(H₂O)₂]²⁺ and four nitrate counter anions In both complexes, cobalt(II) ions are in an octahedral arrangement. Two S, N bidentate AMTTO ligands are coordinated to both Co(II) ions. The coordination sphere of Co1 is completed by two acetonitrile molecules, and these positions are occupied by water molecules for Co2.

Graphic Abstract

A co-crystal of cobalt(II) compound was isolated from the reaction of Co(NO₃)₂?6H₂O and 4-amino-3-mercapto-6-methyl-5-oxo-1,2,4-triazine in acetonitrile as solvent.

     

Crystal Structures of Two Aromatic Zinc(II) Carboxylates: [Zn(4-Chlorosalicylato)2(H2O)4]·2theophylline·(H2O)2 and Unique [Zn(5-Chlorosalicylato)2(isonicotinamide)2(H2O)]

Abstract  

The crystal structures of two zinc(II) 4-chloro- and 5-chlorosalicylate complexes, [Zn(4-ClC₆H₃-2-(OH)COO)₂(H₂O)₄]·2tph·(H₂O)₂ (I) and [Zn(5-ClC₆H₃-2-(OH)COO)₂(ina)₂(H₂O)] (II), where tph is theophylline and ina is isonicotinamide, have been determined using X-ray diffraction methods. Crystals of both (I) and (II) are triclinic, space group P-1, with Z = 1 in a cell with a = 7.2220(3), b = 8.59700(10), c = 16.0210(5) ?, α = 75.990(2), β = 83.959(2), γ = 68.455(2)°, V = 897.54(5) ?³ (I) and with Z = 2 in a cell with a = 11.4148(11), b = 11.5327(10), c = 12.0685(13) ?, α = 63.458(6), β = 87.547(8), γ = 89.387(7)°, V = 1419.9(2) ?³ (II). The coordination environment of the zinc(II) atom of compound (I) consists of two unidentate carboxylate oxygen atoms and four oxygen atoms of aqua ligands, forming a distorted octahedral configuration. Two theophylline molecules and the remaining water molecules are bound only by hydrogen bonds. The Zn atom of compound (II) is pentacoordinated with two unidentate carboxylate oxygen atoms, two pyridine nitrogen atoms of isonicotinamide ligands, and the oxygen atom of the aqua ligand, forming a distorted configuration between square pyramid and trigonal bipyramid. In both complexes intramolecular O–H···O hydrogen-bonding interactions are present. In the crystal structures, molecules are linked by intermolecular O–H···O and N–H···O hydrogen bonds. The structures are analyzed and compared to the similar Zn(II) complexes, with the chromophores ZnO₆ and ZnO₃N₂.     

Synthesis and Crystal Structures of pH-Dependent Ni(II) Coordination Polymers with 3-Pyrid-3-ylbenzoic Acid

Abstract  

Two pyridinecarboxylato-bridged coordination polymers[Ni(pbc)₂(H₂O)₂]_n(1) and {[Ni(pbc) ₂ (H₂O)]·H₂O}_n (2)(Hpbc = 3-Pyrid-3-ylbenzoic acid) have been synthesized by the hydrothermal method and characterized by elemental analysis, IR spectrum and single crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P2₁/c with a = 9.519(5) ?, b = 9.417(5) ?, c = 11.701?, β = 98.086(5)°, V = 1038.5(9) ?³, Z = 2. Compound 2 crystallizes in monoclinic, space group P2₁/c with a = 10.490(2) ?, b = 12.920(3) ?, c = 16.074?, β = 95.97(3)°, V = 2166.7(8) ?³, Z = 4. X-ray diffraction analysis reveals that all pbc⁻ ligands act as diconnectors to link two Ni(II) centers and adopt one coordination mode: μ₂−N, O in compound 1 and the ligands adopt two coordination modes: μ ₂ −N, O and μ ₃ − N, O, O in compound 2.     

Ligand Substitution Chemistry of the Diphosphine Ligand endo,endo-2,3-Bis(diphenylphosphinomethyl)-5-norbornene (dpmn): Syntheses and X-ray Diffraction Structures of PtCl2(dmn) and PtMe2(dpmn)

Abstract  The reaction of phosphine ligand endo,endo-2,3-bis(diphenylphosphinomethyl)-5-norbornene (dpmn) with PtCl₂(cod) and PtMe₂(cod) yields PtCl₂(dpmn) (2) and PtMe₂(dpmn) (4), respectively. Treatment of 2 with excess MeLi or MeMgCl also furnishes 4 in good yield. Both new platinum compounds have been isolated and characterized by NMR spectroscopy (¹H and ³¹P), elemental analyses, and X-ray crystallography. 2 Crystallizes, as the CH₂Cl₂ solvate, in the orthorhombic space group Pnma, a = 18.062(3) ?, b = 16.602(3) ?, c = 11.088(2) ?, V = 3,324.7(9) ?³, Z = 4, D _cacl = 1.681 mg/m³; R = 0.0432, R _w = 0.0759 for 3,755 observed reflections with I > 2σ(I). 4 Crystallizes, as the CH₂Cl₂ solvate, in the orthorhombic space group Pnma, a = 17.969(3) ?, b = 16.689(3) ?, c = 11.237(2) ?, V = 3,370(1) ?³, Z = 4, D _cacl = 1.610 mg/m³; R = 0.0268, R _w = 0.0665 for 4,098 observed reflections with I > 2σ(I). The solid-state structures of 2 and 4 confirm the coordination of the platinum(II) center by the seven-membered chelating dpmn ligand; 2 and 4 represent the first structurally characterized examples of organometallic compounds based on the endo,endo-2,3-bis(diphenylphosphinomethyl)-5-norbornene ligand. Graphical Abstract  The new platinum(II) compounds PtCl₂(dpmn) (2) and PtMe₂(dpmn) (4) have been synthesized, and their structures established by NMR spectroscopy (¹H and ³¹P) and X-ray crystallography. Compounds 2 and 4 are the first structurally characterized examples of organometallic compounds containing the endo,endo-2,3-bis(diphenylphosphinomethyl)-5-norbornene (dpmn) ligand.