Study of the Interaction of Bis(4‐pyridylthio)methane with Copper(II) Chloride and Bromide

The new ligand bis(4‐pyridylthio)methane (4‐bpytm) ( 1 ) and its complexes [CuX₂(4‐bpytm)] and [CuX₂(4‐bpytm)₂] (X = Cl and Br) ( 2 – 5 ) have been prepared and characterized by elemental analysis, IR‐Raman, UV/Vis spectroscopy. The structures of (4‐bpytm) ( 1 ), [CuCl₂(4‐bpytm)₂] ( 3 ) and [CuBr₂(4‐bpytm)₂] ( 4 ) were determined by single‐crystal X‐ray diffraction analysis. X‐ray analysis of the 1:2 derivatives reveals that the copper atom has a distorted (4 + 2) octahedral environment. The copper atom is coordinated by four nitrogen atoms from four bridging 4‐bpytm ligands and two halogen atoms. The axial Cu–N bonds are considerably longer than the equatorial Cu–N bonds owing to JahñTeller distortion. CuX₂ units are linked to each other through bridging 4‐bpytm ligands to form a 2D interpenetrated coordination polymer. The structural parameters of the 4‐bpytm ligand in these complexes were compared with those of the free ligand.     

Syntheses and Characterization of Two Coordination Polymers Constructed by the Ligand 3,5‐Bis(pyridin‐4‐ylmethoxy)benzoic Acid

Two coordination polymers, namely [Zn(L1)(OAc)]·H₂O ( 1 ) and [Cd(L1)₂] ( 2 ), where L1 = 3,5‐bis(pyridin‐4‐ylmethoxy)benzoic acid, have been synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction analysis. Complex 1 has a 2D layer structure in which the hydrogen bonds between lattice water molecules and uncoordinated carboxylate oxygen atoms of the ligand L1 in the adjacent layers extend the 2D layer into a 3D supramolecular architecture. The structure of 2 is a 2D (3,5)‐connected net with (3·5²)(3²·5³·6⁴·7) topology. In addition, the luminescent properties of complexes 1 and 2 have been studied in the solid state at room temperature.     

Synthesis and Structures of Infinite Coordination Polymers from 1,3‐Bis(4‐pyridyl)propane Ligand and Zinc Salts

The reaction of Zn(NO₃)₂‐6H₂O, NH₄SCN and bpp (bpp = 1,3‐bis(4‐pyridyl)propane) in CH₃OH afforded the complex [Zn(NCS)₂(bpp)]_n, 1 , while the reaction of Zn(ClO₄)₂‐6H₂O and bpp in CH₃OH afforded the complex [Zn(ClO₄)₂(bpp)₂]_n, 2 . Both complexes have been characterized by spectroscopic methods and their structures have been determined by X‐ray crystallography. Crystal data for 1 : Orthorhombic, space group P2₁2₁2, a= 12.857(6), b = 14.822(7), c = 4.820(2) Å, β = 90°, V = 918.5(8) ų, Z = 2 with final residuals R1 = 0.0747 and wR2 = 0.1657. Crystal data for 2 : Tetragonal, space group I4/mcm, a = 11.612(1), b = 11.612(1), c = 23.247(9) Å, β = 90°, V = 3135(1) ų, Z = 4 with final residuals R1 = 0.0523 and wR2 = 0.1064. The coordination polymers display a variety of structural architectures, ranging from zigzag chains ( 1 ) and one‐dimensional channel‐type architectures ( 2 ). The effects of the orientation of the nitrogen atom in the pyridine rings on the resultant structures are discussed.     

Grid‐like Cobalt(II) Layered Complex with an Unprecedented Double 1,2‐Bis(1,2,4‐triazole‐1‐yl)methane Bridges

A novel two‐dimensional cobalt complex, [Co(btrm)₂(dca)]ClO₄ ( 1 , btrm = 1,2‐bis(1,2,4‐triazole‐1‐yl)methane, dca = dicyanamide), was synthesized and characterized. X‐ray diffraction analyses reveal that the title complex crystallizes in the monoclinic space group C2/m with a = 29.507(13)Å, b = 17.804(8) Å, c = 14.709(7) Å, β = 119.916(7)°, Z = 12, and R₁ = 0.0784, wR₂ = 0.2041. The cobalt atom involves a six‐coordinated CoN₆ environment, with a distorted octahedral coordination. Two btrm ligands connect the Co^II atoms with the exodentate nitrogen atoms on the 4‐position of triazole rings to form a sixteen‐membered rhombic grid. The unprecedented double btrm bridges and μ_1,5‐dca bridge connect the cobalt atoms to form a two‐dimensional grid‐like layered structure. The spectroscopic and magnetic properties have also been investigated.     

The Structural Systematics of Protonation of Some Important Nitrogen‐base Ligands. II. Some Univalent Anion Salts of Singly Protonated Bis(2‐pyridyl)amine

Syntheses and single crystal X‐ray structure determinations are recorded for a number of normal and ‘acid’ salts of bis(2‐pyridylamine), ‘dpa’, with univalent anions, X, variously hydrated, i.e. [dpaH]X·nH₂O, and [dpaH]X·HX·nH₂O. The ‘normal’ salt arrays so characterized are for X = Br^? (n = 2, isomorphous with the previously described chloride compound) and, I^?, ClO₄^?, ‘tca^?’ (≡ Cl₃CCO₂)^? (all n = 1); acid salt arrays are described for X = NO₃^? and tca (both n = 0). In all cases except those of X = ClO₄^?, NO₃^?, there is one independent formula unit devoid of crystallographic symmetry comprising the asymmetric unit of the structure. In all cases, the proton associated with the cation is ‘chelated’ by the pair of ring nitrogen atoms, disposed ‘endo’; in the tca adducts and the nitrate salt, the total cation is disordered in each case by inversion about a real or putative inversion centre between the rings. In the perchlorate compound, the (ordered) cation lies on a crystallographic 2‐axis, as does the water molecule, and the perchlorate ion, which is disordered about such an axis; in the nitrate compound, the acid hydrogen atom is modelled as disposed on a crystallographic inversion centre between a pair of symmetry‐related nitrate groups, containing, like the Htca adduct, the [XHX]^? moiety rather than a diprotonated cation.     

The X‐ray Single Crystal Structures of an Acid‐functionalized Bis(2‐picolyl)amine (bpa) Ligand with Palladium(II) and Zinc(II) Display Different Intermoleclar Interactions around the Common (H2O)2(anion)2 Motif

This work reports structural investigations on two metal complexes of the functionalized (p‐carboxylatobenzyl)‐bis(2‐picolyl)amine ligand 1 (HL). The complex {[HLPdCl]Cl × H₂O}₂ ( 2_Pd ) has a square‐planar coordination around the Pd ion. It forms discrete dimers by intermolecular hydrogen bonding involving the protonated ligand HL. The coordination around the Zn²⁺ ion in {[(H₂O)LZn]CF₃SO₃ × 2 H₂O}_∞ ( 3_Zn ) is best described as distorted trigonal‐bipyramidal. The N₃O₂ ligand sphere is composed of three nitrogen atoms from the bpa ligand, one water molecule, and a carboxylate oxygen atom from a neighbouring molecule, thus forming infinite chains along the crystallographic a axis. Further intermolecular interactions are based on the same (H₂O)₂(anion)₂ motif as for 2_Pd , but whereas the former forms discrete dimers, 3_Zn forms a more complicated two‐dimensional coordination polymer with additional intermolecular hydrogen bonds.     

A Manganese(II) Coordination Polymer with Ditopic Bis(pyrazol‐1‐yl)borate Bridges

The synthesis and characterization of the ditopic bis(pyrazol‐1‐yl)borate ligand Li₂[p‐C₆H₄(B(C₆F₅)pz₂)₂] is reported (pz = pyrazol‐1‐yl). Compared to the corresponding t‐butyl derivative Li₂[p‐C₆H₄(B(t‐Bu)pz₂)₂], the C₆F₅‐substituted scorpionate is significantly more stable towards hydrolysis. Reaction of Li₂[p‐C₆H₄(B(C₆F₅)pz₂)₂] with two equivalents of MnCl₂ leads to the formation of coordination polymers {(MnCl₂)₂(Li(THF)₃)₂[p‐C₆H₄(B(C₆F₅)pz₂)₂]}_∞ featuring penta‐coordinate Mn^II ions chelated by one bis(pyrazol‐1‐yl)borate fragment and further bonded to three chloride ions. Two of the three chloride ions are also coordinated to a neighbouring Mn^II ion; the third chloro ligand is shared between the Mn^II centre and a Li(THF)₃ moiety.     

Three Coordination Polymers based on 3,5‐Bis(imidazole‐1‐yl)pyridine and Benzoic Acid: Synthesis,Crystal Structures and Photoluminescent Properties

Three metal coordination polymers {[Co(L)₂(H₂O)₂]²⁺ · 2NO₃^–}_n ( 1 ), {[Mn(L)₂(H₂O)₂]²⁺ · 2Cl^– · 3H₂O}_n ( 2 ), and [ZnL(ba)₂]_n ( 3 ) [L = 3,5‐bis(imidazole‐1‐yl)pyridine and Hba = benzoic acid] were synthesized and structurally characterized by IR spectroscopy, elemental analysis, X‐ray powder diffraction, and X‐ray single crystal diffraction. Complex 1 shows a one‐dimensional (1D) chain structure. Adjacent chains are connected by hydrogen bonding and nitrate groups to form a 3D network. Complex 2 features a 2D layer structure. A three‐dimensional network is constructed through the cluster consisting of two chloride ions and three water molecules. Complex 3 shows a 1D zigzag chain structure that further twists together to form a 3D network. The X‐ray powder diffraction patterns were compared with the simulated ones. Moreover, the luminescent properties of 1 – 3 were investigated in the solid state at room temperature, and the thermogravimetric analyses were carried out to study the thermal stability of the three complexes.     

Structure and Bonding in Bis(1‐naphthyl) Diselenide and Bis{[2‐(N,N‐dimethylamino)methyl]phenyl} Tetraselenide,and Their Brominated Derivatives

The formation and crystal structures of bis(1‐naphthyl) diselenide ( 1 ) and bis{[2‐(N,N‐dimethylamino)methyl]phenyl} tetraselenide ( 2 ) are described. Whereas 1 can be produced in good yields, 2 is formed only as a minor product together with the known main product, bis{[2‐(N,N‐dimethylamino)methyl]phenyl} diselenide. The composition of the reaction mixture is semi‐quantitatively estimated by ⁷⁷Se NMR spectroscopy and DFT calculations. The effect of the n²→σ*(Se–Se) and π→σ*(Se–Se) secondary bonding interactions on the Se–Se bonds is discussed both by DFT calculations and comparison with literature, as available. The bromination of 1 yields monomeric (1‐naphthyl)selenenyl bromide ( 3 ) in good yields. That of the reaction mixture of (C₆H₄CH₂NMe₂)Se_x (x = 2–4) and Se₈ afforded (C₆H₄CH₂NMe₂H)₂[SeBr₄] ( 4 ) and (C₆H₄CH₂NMe₂H)₂[SeBr₆] ( 5 ) in addition to (C₆H₄CH₂NMe₂)SeBr, which has been previously reported.     

Synthesis,Spectroscopic and Structural Aspects of Mono‐ and Diorganothallium(III) Complexes of 2, 6‐Diacetylpyridine Bis(thiosemicarbazone) (H2DAPTSC) — A New Coordination Mode of the HDAPTSC— Anion

The reaction of 2, 6‐diacetylpyridine bis(thiosemicarbazone) (H₂DAPTSC) with dimethylthallium hydroxide yielded the complexes [(TlMe₂)₂(DAPTSC)] and [TlMe₂(HDAPTSC)]. The structure of [TlMe₂(HDAPTSC)], determined by X‐ray diffractometry, exhibits a hitherto unknown coordination mode of the HDAPTSC^— anion in which its deprotonated thiosemicarbazone chain coordinates one metal atom through its sulphur and hydrazinic N atoms while a second metal atom is weakly coordinated through the S atom of the undeprotonated thiosemicarbazone chain. Each thallium atom is coordinated in both ways, with the result that the [TlMe₂(HDAPTSC)] units are linked in infinite helical chains in the direction of the b axis. When reacting with diphenylthallium(III) hydroxide, H₂DAPTSC induced a dephenylation process which led to the monophenylthallium(III) complex [TlPh(DAPTSC)]. Recrystallization from acetone yielded crystals of [TlPh(DAPTSC)]·C₃H₆O in which X‐ray diffractometry showed DAPTSC^2— to be pentadentate, coordinating through its sulphur, azomethine N and pyridine N atoms. The ¹H, ¹³C and ²⁰⁵Tl NMR data of [TlPh(DAPTSC)] indicate that its solid state molecular structure persists in DMSO solution, while those of [TlMe₂(HDAPTSC)] indicate rapid alternation between coordination of the metal atom to one of the HDAPTSC^— thiosemicarbazone chains and its coordination to the other.     

The Coordination Chemistry of Iron with the 1,4‐Bis(2‐pyridyl‐methyl)piperazine Ligand

The behaviour of Fe^II and Fe^III ions in combination with the potential ligand 1,4‐bis(2‐pyridyl‐methyl)piperazine (BPMP) under anhydrous conditions has been investigated. BPMP has been reacted with FeCl₂, FeCl₃ and [Fe(OTf)₂(MeCN)₂]. This led to the isolation of four new complexes, which were fully characterized and structurally investigated by single crystal X‐ray diffraction. It turned out that in the presence of chloride co‐ligands Fe^III favours the tetradentate coordination mode of BPMP with the piperazine unit in a boat configuration, like for instance in [BPMP(Cl)Fe(μ‐O)FeCl₃] or [BPMP‐FeCl₂][FeCl₄], ( 1 ). However, the employment of FeCl₂ leads to the formation of a coordination polymer [BPMP‐FeCl₂]_n, ( 2 ), containing the piperazine ring in a chair configuration binding to two iron centres each. 2 can only be dissolved in very polar solvents like dmf which is capable of breaking up the polymeric structure under formation of [Cl₂(dmf)Fe(μ‐BPMP‐1κ²N,N:2κ²N,N))Fe(dmf)Cl₂]·2 dmf, ( 3 ). In contrast, using [Fe(OTf)₂(MeCN)₂] instead of FeCl₂ as the starting material leads to a mononuclear Fe^II complex with BPMP bound in the desirable tetradentate fashion: [BPMP‐Fe(OTf)₂], ( 4 ). Unlike other complexes with tetradentate N/py ligands the two residual ligands in 4 are bound almost trans to each other with the potential to adopt a cis orientation under oxidising conditions, and it will be interesting to exploit its catalytic properties in future.     

Syntheses,Crystal Structures,and Photocatalytic Activities of Three Copper Coordination Polymers Based on Bis(1H‐imidazol‐4‐yl)benzene/3‐(2‐Pyridyl)pyrazole

Three copper(II) coordination polymers (CuCPs), namely, [Cu_0.5(1,4‐bib)(SO₄)_0.5]_n ( 1 ), {[Cu(1,3‐bib)₂(H₂O)] · SO₄ · H₂O}_n ( 2 ), and [Cu(bpz)(SO₄)_0.5]_n ( 3 ), were assembled from the reaction of three N‐donors [1,4‐bib = 1,4‐bis(1H‐imidazol‐4‐yl)benzene, 1,3‐bib = 1,3‐bis(1H‐imidazol‐4‐yl)benzene, and Hbpz = 3‐(2‐pyridyl)pyrazole] with copper sulfate under hydrothermal conditions. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectroscopy, powder X‐ray diffraction (PXRD), and thermogravimetric analyses (TGA). Structure analyses reveal that complex 1 is a 3D 6‐connected {4¹² · 6³}‐ pcu net, complex 2 is a fourfold 3D 4‐connected 6⁶‐ dia net, whereas complex 3 is a 1D snake‐like chain, which further expanded into 3D supramolecular architectures with the help of C–H ··· O hydrogen bonds. Moreover, the photocatalytic tests demonstrate that the obtained CuCPs are photocatalysts in the degradation of MB with the efficiency is 86.4 % for 1 , 75.3 % for 2 , and 91.3 % for 3 after 2 h, respectively.     

Pseudohalide‐directed Assembly of Two Zinc(II) Coordination Polymers with a 3,4‐Bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole Tecton

The zinc(II) pseudohalide complexes {[Zn(L³³⁴)(SCN)₂(H₂O)](H₂O)₂}_n ( 1 ) and [Zn(L³³⁴)(dca)₂]_n ( 2 ) were synthesized and characterized using the ligand 3,4‐bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole (L³³⁴) and ZnCl₂ in presence of thiocyanate (SCN^–) and dicynamide [dca, N(CN)₂^–] respectively. Single‐crystal X‐ray structural analysis revealed that the central Zn^II atoms in both complexes have similar octahedral arrangement. Compound 1 has a 2D sheet structure bridged by bidentate L³³⁴ and double μ_N,S‐thiocyanate anions, whereas complex 2 , incorporating with two monodentate dicynamide anions, displays a two‐dimensional coordination framework bridged by tetradentate L³³⁴ ligand. Structural analysis demonstrated that the influence of pseudohalide anions plays an important role in determining the resultant structure. Both complexes were characterized by IR spectroscopy, microanalysis, and powder X‐ray diffraction techniques. In addition, the solid fluorescence and thermal stability properties of both complexes were investigated.     

Synthesis,Structure, and Magnetic Characterization of a Series of Iron(II) Coordination Frameworks with 2, 6‐Bis(1, 2,4‐triazole‐4‐yl)pyridine

Based on the bis‐triazole ligand 2, 6‐bis(1, 2,4‐triazole‐4‐yl)pyridine (L), the triazole‐iron(II) complexes [Fe(L)₂(dca)₂(H₂O)₂] · 2H₂O ( 1 ) (Nadca = sodium dicyanamide), {[Fe(μ₂‐L)₂(H₂O)₂]Cl₂}_n ( 2 ), and {[Fe(μ₂‐L)₂(H₂O)₂](ClO₄)₂ · L · H₂O}_n ( 3 ) were isolated by solvent diffusion methods. When iron(II) salts and Nadca were used, compound 1 was isolated, which contains mononuclear Fe(L)₂(dca)₂(H₂O)₂ units. When FeCl₂ or FeClO₄ were used, one‐dimensional (1D) cation iron(II) chains ( 2 ) and two‐dimensional (2D) cation iron(II) networks ( 3 ) were isolated indicating anion directing structural diversity. Moreover, variable‐temperature magnetic susceptibility data of 1 – 3 were recorded in the temperature range 2–300 K. The magnetic curve of complex 2 was fitted by using the classical spin Heisenberg chain model indicating anti‐ferromagnetic interactions (J = –5.31 cm^–1). Obviously complexes 1 – 3 show no detectable thermal spin crossover behaviors, the lack of spin‐crossover behavior may be correlated with FeN₄O₂ coordination spheres in 1 – 3 .     

2,2‐Bis(5‐tetrazolyl)propane as Ligand in Energetic 3d Transition Metal Complexes

This contribution covers the preparation and characterization of 2,2‐bis(5‐tetrazolyl)propane (5‐DTP) ( 1 ). The bridged bitetrazole is used as a neutral nitrogen‐rich ligand in 3d transition metal(II) based complexes for the first time and can be synthesized via [2+3] cycloaddition from sodium azide and dimethylmalononitrile. The combination with different anions (e.g., perchlorate, nitrate, sulfate, and chloride) yields materials with widely varying physicochemical properties. The obtained coordination compounds were characterized using low‐temperature single‐crystal X‐ray diffraction (except 14 ), IR spectroscopy, elemental analysis, and DTA (except 16 ). The sensitivities toward external stimuli (impact and friction) were determined according to the Bundesamt für Materialforschung und ‐prüfung (BAM) standard methods together with its sensitivities against electrostatic discharge (except 16 ). Complexes 10 and 14 were characterized in laser ignition experiments. For determination of the compounds' deflagration to detonation transition (DDT) capability, hot plate and hot needle tests were performed for the zinc(II) and copper(II) perchlorate complexes.     

Modular Construction,Structures, and Magnetic Properties of Two Manganese Coordination Polymers Based on 3,5‐Bis(2–carboxylphenoxy)benzoic Acid

Two manganese(II) coordination polymers, namely, [Mn_1.5(BCB)(bpy)_1.5(H₂O)]_n ( 1 ), and [Mn(HBCB)(bibp)₂(H₂O)] ( 2 ), were assembled from the mixed ligands of the flexible tripodal ligand of 3,5‐bis(2‐carboxylphenoxy)benzoic acid (H₃BCB) and two rigid N‐donors [bpy = 4,4′‐bipyridine, and bibp = 4,4′‐bis(imidazolyl)biphenyl]. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectra, powder X‐ray diffraction (PXRD), and thermogravimetric (TG) analyses. Structural analysis reveals that complex 1 is a 3D (3,4,6)‐connected {5 · 6²}₂{5⁶ · 6⁴ · 7 · 8² · 9²}{6⁴ · 8 · 9} net based on two kinds of inorganic nodes of dinuclear {Mn₂(COO)₂} SBUs and Mn(2) ions. Complex 2 is a hydrogen bonds based 3D supramolecule with 6‐connected {4¹² · 6³}‐ pcu net. Besides, the variable‐temperature susceptibilities of 1 and 2 were investigated.     

Syntheses,Crystal Structures,and Magnetic Properties of Two Cobalt Coordination Polymers Constructed From 1,3‐Bis(2,4‐dicarboxyphenyl) Benzene and Bis(imidazole) Linkers

Abstract. The 3D cobalt(II) coordination polymers [Co_1.5(HDDB)(1,4‐bib)_1.5(H₂O)]_n ( 1 ), and {[Co₂(DDB)(1,3‐bib)₂(μ₂‐H₂O)] · H₂O}_n ( 2 ) were assembled by mixed‐ligand synthetic strategy [H₄DDB = 1,3‐bis(2,4‐dicarboxyphenyl) benzene, 1,3‐bib = 1,3‐bis(1H‐imidazol‐4‐yl)benzene, and 1,4‐bib = 1,4‐bis(1H‐imidazol‐4‐yl)benzene]. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectroscopy, powder X‐ray diffraction (PXRD), and thermogravimetric (TG) analyses. Single X‐ray diffraction analysis reveals that complex 1 is an interestingly 3D (3,3.6)‐connected (6³)₄(6⁵ · 8⁸ · 10²) net, and complex 2 is an unprecedented dinuclear [Co₂(COO)(μ₂‐H₂O)] SBUs based 3D (3,6)‐connected (3 · 6 · 7)(3² · 4³ · 5⁴ · 6³ · 7 · 8²) net. Additionally, the magnetic properties of 2 were investigated.     

3D Luminescent Copper(I) Iodide Coordination Polymer Based on Cu4I4 Clusters and an Ethyl‐bridging Bis(triazole) Ligand

The copper‐iodine based coordination polymer [Cu₄I₂(bmte)]_n ( 1 ) [H₂bmte = 1,2‐bis(5‐methyl‐1H‐1,2,4‐triazol‐3‐yl)ethane] was synthesized using cuprous iodide and a flexible 3‐substituted, ethyl‐bridging bis(triazole) ligand under solvothermal conditions. X‐ray diffraction analysis reveals that compound 1 shows a 3D framework containing Cu₄I₄ clusters and alternating left‐ and right‐handed [Cu(triazole)] helices, which result in a (4,8)‐connected fluorite (flu) topological network. Moreover, compound 1 exhibits orange phosphorescence with the emission maxima at 590 nm in the solid state at room temperature.     

Substituted 2,2′‐Bis(2‐oxidobenzylideneamino)‐4,4′‐dimethyl‐1,1′‐biphenyl Complexes of Zinc

The condensation reaction of 2,2′‐diamino‐4,4′‐dimethyl‐6,6'‐dibromo‐1,1′‐biphenyl with 2‐hydroxybenzaldehyde as well as 5‐methoxy‐, 4‐methoxy‐, and 3‐methoxy‐2‐hydroxybenzaldehyde yields 2,2′‐bis(salicylideneamino)‐4,4′‐dimethyl‐6,6′‐dibromo‐1,1′‐biphenyl ( 1a ) as well as the 5‐, 4‐, and 3‐methoxy‐substituted derivatives 1b , 1c , and 1d , respectively. Deprotonation of substituted 2,2′‐bis(salicylideneamino)‐4,4′‐dimethyl‐1,1′‐biphenyls with diethylzinc yields the corresponding substituted zinc 2,2′‐bis(2‐oxidobenzylideneamino)‐4,4′‐dimethyl‐1,1′‐biphenyls ( 2 ) or zinc 2,2′‐bis(2‐oxidobenzylideneamino)‐4,4′‐dimethyl‐6,6′‐dibromo‐1,1′‐biphenyls ( 3 ). Recrystallization from a mixture of CH₂Cl₂ and methanol can lead to the formation of methanol adducts. The methanol ligands can either bind as Lewis base to the central zinc atom or as Lewis acid via a weak O–H ··· O hydrogen bridge to a phenoxide moiety. Methanol‐free complexes precipitate as dimers with central Zn₂O₂ rings.     

Über das Donor‐Verhalten von Bis(pyrazolyl)‐Schwefel‐Derivaten

The Donor Properties of Bis(pyrazolyl)‐Sulfur Derivatives From the reactions of bis(pyrazolyl)sulfane S(pz)₂ ( 1 ) with the fluoro Lewis acids BF₃ and AsF₅ in liquid SO₂ the 1:2‐adducts S(pz·BF₃)₂ ( 2 ) and S(pz·AsF₅)₂ ( 3 ) are obtained. 1 reacts with [Co(SO₂)₄(FAsF₅)₂] to give the doubly bridged FAsF₄F dimeric complex [Co{S(pz)₂}(FAsF₅)(SO₂)(μ‐FAsF₄F)]₂ ( 5 ). From F₂S(pz)₂ and [Ni(SO₂)₆](AsF₆)₂, the fluorocubane [Ni₄F₄{S(pz)₂}₄(μ‐FAsF₄F)₂](AsF₆)₂·4SO₂ ( 8 ) is isolated. The X‐ray structures of the compounds 2 , 3 , 5 and 8 are reported.