Synthesis and crystal structure of a novel zinc(II) coordination polymer with mixed ferrocenyl diketone and bipyridine ligands

A novel zinc(II) coordination polymer [Zn(fca)₂(bpe)]_n·2nH₂O (bpe=1,2-bis(4-pyridyl)ethene, fca=C₅H₅FeC₅H₄C(OH)CHCOCH₃) was obtained by the reaction of Zn(OAc)₂·2H₂O with bpe and 1-ferrocenylbutane-1,3-dione (ferrocenoylacetone, Hfca) in methanol solution. X-ray structural analysis reveals that the compound contains two kinds of ligands: one is the 1,2-bis(4-pyridyl)ethene ligand, directly bridging zinc(II) centers to form a one-dimensional chain [Zn(bpe)]_n, the other is the enolized ferrocenylacetone chelating the central ion. The zinc(II) ion is in an elongated octahedral environment with four oxygen atoms from two distinct enolized ferrocenoylacetone, two nitrogen atoms of the bridging 1,2-bis(4-pyridyl)ethene ligands.     

Structural Characterization of a Cu(I) Coordination Polymer Constructed by Weak Intermolecular Cu–Cl⋯Cl–Ar Interaction

The copper(I) complex [Cu(DPPEO)(L₁)Cl] · CH₃CN (1) (DPPEO = 1,2-bis(diphenylphosphino)ethane monoxide; L₁ = 5,7-dimethyl-2-chloronaphthyridine) was prepared by reacting L₁ with CuCl in the presence of DPPE. The compound has been characterized by X-ray diffraction analysis. Compound 1 is a tri-coordinated mononuclear complex, which forms one-dimensional chain through intermolecular halogen-halogen bonds.     

A Novel 3D-Supramolecular Coordination Polymer Based on CuCN,Ph<Subscript>3</Subscript>Sn Cation and Quinoxaline

Reaction of Ph₃SnCl and K₃[Cu(CN)₄] with quinoxaline (qox) at room temperature affords the novel 3D-supramolecular coordination polymer (SCP) _∞³[Cu₂(CN)₄·(Ph₃Sn)₂·qox], I, as the first example of the organotin-CuCN SCP containing the Ph₃Sn fragment. The structure of I displays two Cu(CN)₂ building blocks connected by a Ph₃Sn cation and qox ligand creating the rhombic [Cu₂(μ-CN)₂] motif. The structure of I contains three different fused rings, the minicycle [Cu₂(μ-CN)₂], the 18-atomic [Cu₄(Ph₃Sn)₂(CN)₄(qox)₂], and the 24-atomic [C₈N₈Cu₄(Ph₃Sn)₄] rings, which create a non-interpenetrating 3D-network. These rings form a box-like structure with cavities suitable to accommodate bulky phenyl groups. SCP I belongs to the rapidly growing family of supramolecular assemblies containing the quite unusual [Cu₂(μ-CN)₂] motif, the repeated appearance of which raises the question whether cuprophilic interactions therein are the basic cause of the existence of I.     

1,3-Bisdiphenylphosphinoferrocenes: the unexpected 2,5,-dilithiation of dibromoferrocene towards a new area of ferrocene-ligand chemistry

The synthesis and characterization of 1,3-bis-diphenylphosphinoferrocene is described for the first time. The ligand is obtained as a byproduct of the ortho-lithiation of 1,1′-dibromoferrocene, as a consequence of the dilithiation of one of the cyclopentadienyl rings. The intermediate compound 1,1′-dibromo-2,5-bis-(diphenylphosphino)ferrocene which is the precursor compound to the new ligand has been structurally characterized. Further reaction of 1,1′-dibromo-2,5-bis-(diphenylphosphino)ferrocene with n-butyllithium followed by quenching with chlorodiphenylphosphine affords the new 1,2,3,1′-tetrakis(diphenylphosphino)ferrocene, while the similar reaction of 1,1′-dibromo,2,2′-bis(diphenylphosphino)ferrocene gives 1,1′,2,2′-tetrakis(diphenylphosphino)ferrocene.     

Structural Influence of the Ligand Geometry on Construction of Coordination Polymers Formed from Silver(I) Chloride Ribbons and Bipodal Nitrogen Donor Ligands

An assembly of adducts of silver nitrate and KCl and bipodal nitrogen donor ligands, 4,4′-bipyridine (bpy), trans-1,2-bis(4-pyridyl)ethylene (tbpe) or 1,2-bis(4-pyridyl)ethane (bpe), at room temperature affords new supramolecular coordination polymers (SCP), [AgCl·bpy] (1), [(AgCl)₂·tbpe] (2) and [(AgCl)₃·(bpe)₂] (3). X-ray single crystal analyses reveal that 1–3 have 3D-supramolecular networks composed of different types of infinite 1D-ribbons of ladder, 1, and staircase, 2 and 3, structures formed from fused minicyle {Ag₂(μ₃-Cl)₂} motifs, which are bridged by the nitrogen donor ligands to form 2D-layers. The 2D-layers are interconnected by extensive hydrogen bonds and π–π stacking thereby creating 3D-networks. The products are also characterized by IR and electronic absorption spectra. SCP 1–3 display strong fluorescence in the solid state at room temperature.     

Molecular switching of nickel(ΙΙ) complexes using a hemilabile N,N′-bis(β-carbamoylethyl)1,2-diaminocyclohexane ligand

The reaction of NiCl₂·6H₂O with one equivalent hemilabile diaminodiamide ligand N,N′-bis(β-carbamoylethyl)1,2-diaminocyclohexane (1) gave a pale blue compound [Ni(C₁₂H₂₄N₄O₂)(H₂O)₂]₂·3H₂O·4Cl (2). With more than one equivalent ligands, 2 was transformed to a yellow species [Ni(C₁₂H₂₂N₄O₂)]·3H₂O (3) by the Ni–O to Ni–N bond rearrangement at two amide sites of the complex. The color change could be described as a pH dependent isomerization of the ligand. The results presented could be useful in the design of new Ni(II)-based switching materials.     

Cobalt(II), Zinc(II) and Cadmium(II)-Squarate Complexes with N-Methylimidazole

Three M(II)-squarate complexes, [Co(sq)(H₂O)(Nmim)₄] (1), [Zn(μ_1,3-sq)(H₂O)₂ (Nmim)₂] _n (2) and [Cd(μ_1,3-sq)(H₂O)₂(Nmim)₂] _n (3) (sq = squarate, Nmim = N-methylimidazole) have been synthesized and characterized by elemental, spectral (IR and UV–Vis.) and thermal analyses. The molecular structures of the complexes have been investigated by single crystal X-ray diffraction technique. The squarate ligand acts as two different coordination modes as a monodentate (in 1) and bis(monodentate) (O ^1– O ³ ) bridging ligand (in 2, 3). The Co(II) atom has a distorted octahedral geometry with the basal plane comprised of three nitrogen atoms of Nmim ligands and a oxygen atom of squarate ligand. The axial position is occupied by a nitrogen atom of Nmim and one aqua ligand. The crystallographic analysis reveals that the crystal structures of 2 and 3 are one-dimensional linear chain polymers along the c and b axis, respectively. The configuration around each metal(II) ions are distorted octahedral geometry with two nitrogen atoms of trans-Nmim, two aqua ligands and two oxygen atoms of squarate-O¹,O³ ligand. These chains are held together by the C–H···π, π···π and hydrogen-bonding interactions, forming three-dimensional network.     

Hexachloroplatinate(IV) anion-induced cucurbit[5]uril and cucurbit[8]uril supramolecular assemblies with linear channels

Two Q[n]-based porous compounds, Q[5]·[PtCl₆]^2 −·2H₃O·12H₂O and 2Q[8]·[PtCl₆]^2 −·2H₃O·74H₂O in cooperating the hexachloroplatinate(IV) anion ([PtCl₆]^2 −) as an inorganic structure directing agent are demonstrated. The driving forces for the formation of such novel Q[n]-based porous compounds are considered to be the outer surface interactions of Q[n]s, including dipole interactions between Q[n]s and ion-dipole interactions between [PtCl₆]^2 − anions and Q[n]s. Moreover, the Q[5]-based porous compound displays absorption distinctness for tetrachloromethane, whereas the Q[8]-based porous compound displays absorption distinctness for methanol.     

Ligand Controlled Highly Selective Copper‐Catalyzed Borylcuprations of Allenes with Bis(pinacolato)diboron

Copper‐catalyzed highly selective borylcuprations of allenes with bis(pinacolato)diboron produce two different types of alkenylboranes by applying a ligand effect. In the presence of tris(para‐methoxyphenyl)phosphine [P(C₆H₄OMe‐p)₃], the reaction of aryl‐1,2‐dienes affords 2‐alken‐2‐yl boronates as the only product with exclusive Z‐geometry; the regioselectivity is switched to afford the 1‐alken‐2‐yl boronates as the major products when the bidentate phosphine 2,2′‐bis(diphenylphosphino)biphenyl is used as the ligand.     

Unexpected Reaction of 2,2′‐Bipyridyl‐cycloocta‐1,5‐diene‐nickel(0) with Acetone and Dioxygen

The reaction of (bipy)Ni(cod) ( 1 ) (bipy = 2,2′‐bipyridyl, cod = cycloocta‐1,5‐diene) with dioxygen and acetone at −20°C affords (bipy)Ni(C₉H₁₆O₃) ( 2 ) (C₉H₁₆O₃^2— = 2,4,6,6‐tetramethyl‐tetrahydropyran‐2,4‐diolate), which has been characterized by NMR, MS and an X‐ray crystal structure determination. Acidolysis of compound 2 with two equivalents of acetyl acetone (Hacac) yields (bipy)Ni(acac)₂ and C₉H₁₈O₃ ( 3 ) (2,4,6,6‐tetramethyl‐tetrahydropyran‐2,4‐diol), a cyclic trimer of acetone.     

On the Photomagnetic Properties of the Binuclear Spin Crossover Complexes {[Fe(bt)(NCSe)<Subscript>2</Subscript>]<Subscript>2</Subscript>(bpym)} and {[Fe(bpym)(NCSe)<Subscript>2</Subscript>]<Subscript>2</Subscript>(bpym)}

Infrared and visible light irradiation effects on the spin state of iron(II) ions have been investigated in the binuclear molecules {[Fe(bt)(NCSe)₂]₂(bpym)} (4) and {[Fe(bpym)(NCSe)₂]₂(bpym)} (2). For compound 2 we could observe LIESST and partial reverse-LIESST effects under visible and infrared light irradiation, respectively. Compound 4 exhibits a wavelength-selective photoconversion at 10 K from the low spin (LS–LS) ground state of the binuclear molecule to the metastable high spin (HS–HS) state under visible (785 or 532 nm) light irradiation or to the metastable HS–LS state under infrared (1,342 nm) light irradiation. In addition we also observed the reverse (HS–HS → HS–LS) and the cascade (LS–LS → HS–LS → HS–HS) photoconversions as well. These phenomena lead to complex and original photomagnetic behaviour due to the intramolecular magnetic coupling. This article is dedicated to Professor Didier Astruc in honor of his scientific achievements, with friendship and sincere respect.     

Bis[4-(methylthio)phenylmethyleneaminophenyl] disulfide, 2-[4-(methylthio)phenyl]-2,3-dihydro-1,3-benzothiazole,and its nickel(II) and cobalt(II) complexes: Synthesis,adsorption on gold surface and electrochemical characterization

2-[4-(Methylthio)phenyl]-2,3-dihydro-1,3-benzothiazole (1) and bis[4-(methylthio)phenylmethylene-aminophenyl] disulfide (2) were synthesized. Novel coordination compounds of Ni(II) and Co(II) with 2-[4-(methylthio)phenylmethyleneamino]thiophenol, M(1)₂ (M=Co (3); M=Ni (4)), were prepared by reacting 1 with M(OAc)₂·6H₂O or MCl₂·6H₂O in EtOH solution. The structure of 2 was proved by X-ray crystallography. Electrochemical behavior of 1–4 in CH₃CN solution and at the surface of a gold electrode was studied by cyclic voltammetry. The modification of the electrode by ligand 1 and its complexes with Ni²⁺ and Co²⁺ is described in detail. Two procedures were used to obtain a self-assembled monolayer of a metal complex on the gold surface: the adsorption of prepared coordination compound 3 or 4 on the electrode and the initial modification of the electrode with ligand 1 followed by the formation of a coordination complex between the ligand adsorbed on the electrode and a metal salt occurring in solution. On the basis of the electrochemical data, it was found that the structure of complexes formed on the surface differs from that of the complexes produced in solution.     

Solution and solid-state photoluminescence of dinuclear Pb(II) dicarboxylate compound with 2,6-bis(benzimidazolyl)pyridine: The lone-pair stereochemistry and its effect on supramolecular interaction

[Pb₂(boa)(Hbbp)₂] has been synthesized by treating 4-carboxylphenoxyacetic (H₂boa) and 2,6-bis(benzimidazolyl)pyridine (H₂bbp) with metal salts under hydrothermal conditions. Adjacent metal centers forms dinuclear metal complex through carboxylato groups as building blocks. The arrangement of the half deprotonated H₂bbp ligand and carboxylate groups exhibits a coordination gap around the Pb(II) ion, occupied possibly by a stereoactive lone pair of electrons on Pb(II), with the coordination environment around the lead atoms is hemidirected. This system is a particularly clear example that coordination sphere of a unique dinuclear Pb(II) compound was controlled by lone pair activity, weak Pb···O interactions, π–π stacking and the hydrogen bonds. The above weak interactions influence differently strong red-shifted effect about the solution and solid-state photoluminescence of the compound, compared to the free ligand.     

Preparation of Zinc(II) Oxide Nanoparticles from a New Nano-Size Coordination Polymer Constructed from a Polypyridyl Amidic Ligand; Spectroscopic, Photoluminescence and Thermal Analysis Studies

A new zinc(II) coordination polymer, {[Zn(bpcdp)₂(DMF)₄](ClO₄)₂·(H₂O)₂}_n (1) bpcdp = 2,6-bis(4-pyridinecarboxamide)pyridine has been synthesized and characterized by IR, ¹HNMR and ¹³CNMR spectroscopy. The single crystal X-ray data of compound 1 shows the zinc(II) atom has been considered as octahedral with ZnN₂O₄ coordination sphere. Two nitrogen atoms of bpcdp ligand and four oxygen atoms of DMF molecules have occupied coordination sphere around zinc(II) atoms. The prepared zinc(II) coordination polymer grows in three-dimensional network by hydrogen bonding and π–π stacking interaction. The nanostructure of compound 1 were obtained by sonochemical process and studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), IR and NMR spectroscopy. Thermal stabilities of single crystalline and nano-size samples of compound 1 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The ZnO nanoparticles were obtained by direct calcination of compound 1 at 400 °C and by thermolysis in oleic acid at 200 °C. The obtained zinc(II) oxide nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

Structural diversity and solution behavior of low-valent iridium complexes bearing 1,4-diazabutadiene ligands

Three types of 1,4-diazabutadiene stabilized low-valent iridium complexes, namely [IrCl(cod)(MesDAB)] (1), [IrCl(coe)(MesDAB)] (2) and [IrCl(MesDAB)₂] (3), have been prepared from 1,4-bis(2,4,6-trimethylphenyl)-1,4-diaza-1,3-butadiene (MesDAB) and [IrCl(cod)]₂ or [IrCl(coe)₂]₂, respectively. The complexes have been investigated by NMR spectroscopy and X-ray diffraction experiments. While tetra-coordinated 2 and penta-coordinated 3 maintain their solid state structure in solution, penta-coordinated 1 shows fluxional behavior. The crystal structures determined indicate strong π-backbonding towards the MesDAB ligand in all cases.     

Synthesis and Crystal Structure of Three New Zn(II), Ni(II) and Mn(II) Coordination Polymers Based on Asymmetric Dicarboxylate Ligand

Three new coordination polymers [Zn(pda)(H₂O)]_n (1), [Ni(pda)(bib)_1.5]_n (2) and [Mn₂(pda)₂(bimb)]_n (3) [H₂pda?=?3,4′-biphenyl-dicarboxylic acid, bib?=?4,4′-bis (2-imidazol-1-ylmethyl) biphenyl and bmib?=?4,4′-bis (2-methylimidazol-1-ylmethyl)biphenyl] have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray analyses revealed that that pda ligand acts as bridging ligand, exhibiting rich coordination modes to link metal ions: monodentate, bidentate chelating, bis-monodentate and chelating/bridging fashions. Compound 1 and 2 demonstrate a one-dimensional chain. Compound 3 is a two-dimensional (4,4) layer structure. Furthermore, the solid state luminescence spectrum of compound 1 is investigated at room temperature.     

Synthesis and structural study of tri- and dinuclear palladium complexes of 2,6-bis(diphenylphosphino)pyridine

The bridging ligand 2,6-bis(diphenylphosphino)pyridine, L, was used to synthesize two palladium complexes: Pd₃Cl₆(μ-L)₃ has a C₂ axis passing through an 18-membered macrocyclic ring, in which two cis- and one trans-coordinated palladium(II) atoms are alternately bridged by three L ligands; [Pd₂(μ-L)₂]²⁺ exhibits a rare coordination mode in which two metal–metal bonded palladium(I) atoms (Pd–Pd = 2.5525(7) Å) are each P, N-chelated by one ligand and connected to the bridging phosphorus atom of the other ligand.     

Unexpected Formation of a Doubly Bridged Cyclo-1,2-dithian 1D Coordination Cu<Subscript>2</Subscript>I<Subscript>2</Subscript>-Containing Luminescent Polymer

Abstract  

CuI reacts instantaneously with butanedithiol in MeCN solution to form a sparingly soluble and thermally stable colorless polymeric material 1 of composition [(Cu₂I₂){HS(CH₂)₄SH}] _n . Raman and IR spectroscopy confirm the presence of Cu(I) bound S–H functions. Furthermore, small amounts of the yellow compound [{Cu(μ₂-I)₂Cu}(C₄H₈S₂)₂] _n 2 co-crystallize after several days. If the reaction mixture is exposed to air, polymeric 2 is isolated as the main product. An X-ray diffraction study reveals that 1D polymer 2 is assembled by rhomboid Cu(μ₂-I)₂Cu clusters (d Cu···Cu 2.6843(18) ?), which are linked through the S-atoms of six-membered 1,2-dithian heterocycles, thus generating an infinite ribbon. The low-frequency region in the Raman spectra show a striking similarity suggesting that polymers 1 and 2 bear the same cluster rhomboid Cu(μ₂-I)₂Cu clusters. The photophysics and luminescence properties of 2 have been studied experimentally and by means of DFT/TDDFT calculations.     

A metal-organic coordination polymer based on 1,2-bis(diphenylphosphino)ethane dioxide: Synthesis,crystal structure and fluorescence of [ZnI2{Ph2P(O)-CH2CH2-P(O)Ph2}]n

A zinc coordination polymer, [ZnI₂{Ph₂P(O)-CH₂CH₂-P(O)Ph₂}]_n (1), has been prepared, which features a one-dimensional concavo-convex chain with alternative ZnI₂ and 1,2-bis(diphenylphosphino)ethane dioxide (dppeO₂) moieties. The dppeO₂ ligand adopts the bridging coordination mode between two zinc atoms.     

Solvent Control Over Structural Diversity of Two Copper (II) Complexes Based on Polyaromatic Acid Ligand

Abstract  

A new bipod polyaromatic acid ligand H₂bcm (H₂bcm = {2, 4-bis [(2′-carboxyphenoxy) methyl]-1,3,5-trimethylbenzene}) is prepared and its two novel binuclear coordination compounds, [Cu₂(bcm)₂(CH₃OH)₂]·2CH₃OH (1) and [Cu₂(bcm)₂(CH₃CH₂OH)₂]·2CH₃CH₂OH (2), have been synthesized with copper acetate and H₂bcm ligand in methanol solvent and ethanol solvent respectively, and characterized by the element analysis, IR, TGA and single crystal X-ray diffraction. The results of structural analysis indicate that 1 crystallizes in the triclinic system with space group P1, while 2 crystallizes in the monoclinic system with space group P2₁ /c. Furthermore, 1 adopts μ ₂ -COO⁻ and syn–syn coordination mode with Cu (II)···Cu (II) separation of 2.5868(11) ? and forms 1D zigzag chain structure by O···O interactions. The coordination of 2 is similar to that of 1 except that ethanol molecules are coordinated instead of methanol molecules with Cu (II)···Cu (II) separation of 2.5973(13) ?. Two-dimensional network structures of 1 and 2 are formed through π–π interactions.