SYNTHESIS OF ONE-AND TWO-DIMENSIONAL ZINC AND CADMIUM COMPLEXES WITH 4, 4′-BIPY

Abstract

The zinc(II) and cadmium(II) complexes [Zn(4, 4′-bipy)(SCN)₂]_∞ 1 and [Cd(4, 4′-bipy)-(SCN)₂]_n 2 have been synthesized and their crystal structures determined by X-ray crystallography. Complex 1 is monoclinic, space group C2/c, with a = 18.076(5), b = 5.190(1), c = 17.315(4)Å; β = 115.54(2), V = 1465.8(8)ų, calculated density 1.530gcm^?3, Z = 4. In this compound, the rod-like ligand 4, 4′-bipy bridges Zn(II) centres, and the NCS groups are terminally coordinated. (N-Zn-N) is 108.5°, resulting in the formation of a zigzag Zn-bipy-Zn chain. These chains are arranged in parallel fashion. The 4, 4′-bipy ligands of adjacent layers are separated by 3.95 (Å). Complex 2 is monoclinic, space group C2/c, a = 11.902(2), b = 11.745(2), c = 10.500(2)Å; β = 109.71(3), V = 1381.8(4)ų calculated density 1.849gcm^?3, Z = 4. In this structure, the cadmium(II) ion is slightly distorted octahedral and the SCN groups act as doubly bridging ligands connecting cadmium atoms to form zigzag chains, separated by 4, 4′-bipy to create two-dimensional planes.     

Syntheses,Crystal Structures,and Thermal Behaviors of Two New Metallo‐Organically Templated Pentaborates

Two new cadmium borates, [Cd(en)₃][B₅O₆(OH)₄]₂ · 2H₂O (en = ethylenediamine) ( 1 ) and [Cd(DETA)₂][B₅O₆(OH)₄]₂ (DETA = diethylenetriamine) ( 2 ) were synthesized in a novel procedure under mild solvothermal conditions and characterized by single‐crystal X‐ray diffraction, IR spectroscopy, elemental analysis, and TG–DTA. The compound 1 crystallizes in monoclinic system, space group P2₁/c (No. 14) with a = 8.526(2) Å, b = 23.127(6) Å, c = 15.438(4) Å, β = 94.320(3) °, V = 3035.5(13) Å³, Z = 4. Compound 2 is triclinic, space group P$\bar{1}$ (No. 2), a = 8.632(5) Å, b = 9.418(6) Å, c = 27.856(18) Å, α = 95.415(8) °, β = 91.891(7) °, γ = 93.563 (7) °, V = 2248(2) Å³, Z = 3. The anionic units of the both structures, [B₅O₆(OH)₄]^– are linked by hydrogen bonds to form a three‐dimensional framework with large channels, in which the templating cadmium complex cations are located. The thermal decomposition performance of compound 1 requires three steps, whereas only two steps are needed for compound 2 , which all lead to amorphous phases. These processes are well explained considering the structure and the change in the Cd²⁺ coordination during heating.     

Synthesis,Crystal Structure,and Magnetic Properties of (2,2′‐dipyridylamine)(X−) Copper(II) Complexes (X−: Cyanate,Dicyanamide, Acetate,Thiocyanato)

The synthesis, structure, and magnetic properties of four 2,2′‐dipyridylamine ligand (abbreviated as Hdpa) containing copper(II) complexes. There is one binuclear compound, which is [Cu₂(μ_1,1‐NCO)₂(NCO)₂(Hdpa)₂] ( 1 ), and three mononuclear compounds, which are [Cu{N(CN)₂}₂(Hdpa)₂] ( 2 ), [Cu(CH₃CO₂)(Hdpa)₂·N(CN)₂] ( 3 ), and [Cu(NCS)(Acac)] ( 4 ). Compounds 1 and 4 crystallize in the monoclinic system, space group P2(1)/c and Z = 4, with a = 8.2465(6) Å, b = 9.3059(7) Å, c = 16.0817(12) Å, β = 91.090(1)°, and V = 1233.90(16) ų for 1 and a = 7.6766(6) Å, b = 21.888(3) Å, c = 10.4678(12) Å, β = 90.301(2)°, and V= 1758.8(4) ų for 4 . Compounds 2 and 3 crystallize in the triclinic system, space group P‐1 and Z = 1, with a = 8.1140(3) Å, b = 8.2470(3) Å, c = 9.3120(4) Å, β = 102.2370(10)°, and V = 592.63(4) ų for 2 and a = 7.4780(2) Å, b = 12.5700(3) Å, c = 13.0450(3) Å, β = 96.351(2)°, and V = 1211.17(5) ų for 3 . Complex ( 1 ), the magnetic data was fitted by the Bleaney‐Bowers equation (1). A very good fit was derived with J = 23.96, Θ = ?1.5 (g = 1.97). Complex ( 1 ) shows the ferromagnetism. Complexes ( 2 ), ( 3 ) and ( 4 ) of have the it is the typical paramagnetic behavior of unpaired electrons. Under a low temperature around 25 K, complexes ( 2 ) and ( 3 ) show weak ferromagnetic behavior. They are the cause of hydrogen bonds.     

Syntheses and crystal structures of two cadmium coordination polymers [Cd(2-mBIM)(NCS)(SCN)] n and [Cd2(2-mBIM)2(NO3)2(C4H4O4)(H2O)5] n based on bis(2-methylimidazol-1-yl)methane

Two cadmium(II) coordination polymers, [Cd(2-mBIM)(NCS)(SCN)] _n (1) and [Cd₂(2-mBIM)₂(NO₃)₂(C₄H₄O₄)(H₂O)₅] _n (2) (2-mBIM = bis(2-methylimidazo-1-yl)methane, C₄H₄O₄= succinate), have been synthesized and characterized by X-ray diffraction. Complex 1 crystallizes in the triclinic space group P 1 with a = 9.0770(5) Å, b = 9.4043(4) Å, c = 19.8720(9) Å, α = 101.551(1)°, β = 93.498(1)°, γ = 108.484(1)°, V = 1562.02(13) ų, and Z = 2. Each Cd(II) is octahedrally coordinated and connected with two adjacent Cd(II)'s by double end-to-end thiocyanate bridges, resulting in the formation of 1-D zigzag chains, linked to each other via bridging 2-mBIM giving a 2-D supramolecular framework. Complex 2 crystallizes in the monoclinic space group P2(1)/n with a = 12.6543(6) Å, b = 7.7128(4) Å, c = 17.3089(9) Å, β = 109.3980(10)°, V = 1593.45(14) ų, and Z = 2. Cd(II) is coordinated with oxygen and nitrogens from two independent 2-mBIM, in a cis-configuration to form a 1-D helical structure. A 3-D supramolecular network comprised of succinate anion bridged 1-D helical chains, and weak hydrogen bonds between dimer waters gave 2-D layers.     

Intermetallic Phases in the Ca‐Cu‐Sn System

Twelve ternary alloys in the Ca‐Cu‐Sn system were synthesized as a test on the existing phases. They were prepared from the elements sealed under argon in Ta crucibles, melted in an induction furnace and annealed at 700 °C or 600 °C. Four ordered compounds were found: CaCuSn (YbAuSn type), Imm2, a = 4.597(1) Å, b = 22.027(2) Å, c = 7.939(1) Å, Z = 12, wR2 = 0.080, 1683 F² values; Ca₃Cu₈Sn₄ (Nd₃Co₈Sn₄ type), P6₃mc, a = 9.125(1) Å, c = 7.728(1) Å, Z = 2, wR2 = 0.087, 704 F² values; CaCu₂Sn₂ (new structure type), C2/m, a = 10.943(3) Å, b = 4.222(1) Å, c = 4.834(1) Å, β = 107.94(1)°, Z = 2, wR2 = 0.051, 343 F² values; CaCu₉Sn₄ (LaFe₉Si₄ type), I4/mcm, a = 8.630(1) Å, c = 12.402(1) Å, Z = 4, wR2 = 0.047, 566 F² values. In all phases the shortest Cu‐Sn distances are in the range 2.59‐2.66Å, while the shortest Cu‐Cu distances are practically the same, 2.53‐2.54Å, except CaCuSn where no Cu‐Cu contacts occur.     

Tt‐Tt (Tt = Si,Ge) Dumb‐Bell Structures at Different Valence Electron Concentrations: Ln2MgSi2 (Ln = La,Ce), Yb2Li0.5Ge2, and Yb1.75Mg0.75Si2

The isostructural compounds Yb₂MgSi₂, La_2.05Mg_0.95Si₂, and Ce_2.05Mg_0.95Si₂, as well as Yb₂Li_0.5Ge₂ and Yb_1.75Mg_0.75Si₂, respectively, were synthesized from stoichiometric mixtures of the corresponding elements in sealed Nb‐ ampoules under argon atmosphere. The structures were determined by single crystal X‐ray diffraction: Yb₂MgSi₂ (P4/mbm (No. 127), a = 7.056(1), c = 4.130(1) ų, Z = 2), La_2.05Mg_0.95Si₂ (P4/mbm, a = 7.544(1), c = 4.464(1) ų, Z = 2), and Ce_2.05Mg_0.95Si₂ (P4/mbm, a = 7.425(1), c = 4.370(1) ų, Z = 2), Yb₂Li_0.5Ge₂ (Pnma (No. 62), a = 7.0601(6), b = 14.628(1), c = 7.6160(7) Å, V = 786.5ų, Z = 4), Yb_1.75Mg_0.75Si₂ (Pnma, a = 6.9796(1), b = 14.4009(1), c = 7.5357(1) Å, V = 757.43(2) ų, Z = 4). All compounds contain exclusively Tt‐Tt dumb‐bells (Tt = Si, Ge). The Si‐Si Zintl anions exhibit only very small variations of bond lengths which seem to be more due to cation matrix effects than to effective bond orders.     

Novel modification of anhydrous transition metal oxalates from powder diffraction

The known metal–C₂O₄ structures may be divided into two modifications, α and β. The α‐modification has an order–disorder struxture, revealing one‐dimensional disordering of the metal–oxalate chains, and the β‐modification is ordered. The crystal structures of orthorhombic γ‐MnC₂O₄ {poly[μ‐oxalato‐manganese(II)]; space group Pmna , a = 7.1333 (1), b = 5.8787 (1), c = 9.0186 (2) Å, V = 378.19 (1) ų, Z = 4 and D_x = 2.511 Mg m⁻³} and γ‐CdC₂O₄ {poly[μ‐oxalato‐cadmium(II)]; space group Pmna , a = 7.3218 (1), b = 6.0231 (1), c = 9.2546 (2) Å, V = 408.13 (1) ų, Z = 4 and D_x = 3.262 Mg m⁻³} have been obtained from powder diffraction patterns. The structures are isostructural. Each metal atom in each structure is coordinated by seven O atoms which belong to five oxalate ions. The crystal packing, which contains noticeable cavities in the [101] and [001] directions, is not close packed and essentially differs from the known disordered α‐ and ordered β‐modifications of transition metal oxalates. This modification seems to be metastable. It was found that a spontaneous γ→β phase transition takes place for γ‐CdC₂O₄.     

SYNTHESIS AND STRUCTURES OF DICHLOROTETRAKIS-(PHENYLTHIOUREA) CADMIUM(II) AND CATENA-BIS(THIOCYANATE) BIS(PHENYLTHIOUREA)CADMIUM(II)

Abstract

Two new cadmium(II) complexes with phenylthiourea (PTU), namely Cd(PTU)₄Cl₂ (1) and [Cd₂(NCS)₂(μ₂-SCN)₂(PTU)₂(μ₂-PTU)₂] _n (2), have been prepared and characterized structurally by X-ray diffaction. Complex 1 crystallizes in the monoclinic space group C2/c, with a = 27.057(13), b = 8.108(3), c = 16.751(8) Å, β = 114.46°, V = 3345(3) ų, Z = 4. Complex 2 crystallizes in the triclinic space group P-1, with a = 9.336(3), b = 14.686(5), c = 16.911(5) Å, α = 71.36(2), β = 84.31(2), γ = 72.470(10)°, V = 2095.0(12) ų Z = 4. The structural analysis shows that each metal atom in both the mononuclear complex 1 and polynuclear complex 2 is octahedrally coordinated by four sulfur atoms and two chloro ligands or two nitrogen atoms from the thiocyanate groups, respectively. The PTU ligand can serve as either a monodentate ligand or a μ₂-bridging ligand upon coordination to a metal atom.     

Three Copper(II) Coordination Polymers Constructed by Both Rigid and Flexible Ligands

Three new Copper(II) polymers coordinated by both rigid and flexible ligands, [Cu(bpy)(C₅H₆O₄)]_n ( 1 ), [Cu(bpy)(C₆H₈O₄)]_n ( 2 ), and [Cu₂(bpy)₂(C₆H₈O₄)₂]_n ( 3 ) (bpy = 4,4′‐bipyridine), have been hydrothermally synthesized and structurally characterized. Complex 1 features a box‐like bilayer motif of (4, 4) net. It crystallizes in triclinic space group with cell parameters: a = 8.1395(6) Å, b = 9.43 12(8) Å, c = 10.5473(8) Å, α = 112.1830(1)°, β = 92.423(2)°, γ = 104.752(2)°, V = 716.31(1) ų, Z = 2. Complex 2 crystallizes in triclinic space group with a = 8.8652(4) Å, b = 8.9429(4) Å, c = 10.6390(4) Å, α = 89.520(2)°, β = 69.123(2)°, γ = 75.2440(1)°, V = 758.92(6) ų, Z = 2. Complex 3 crystallizes in monoclinic space group Cc with a = 11.1521(1) Å, b = 15.3961(1) Å, c = 17.7419(1) Å, β = 105.715(3)°, V = 2932.4(5) ų, Z = 4. Complexes 2 and 3 are isomeric with different coordination modes of adipato ligand. Both of them possess the two‐fold interpenetrated 3‐D pcu topological net.     

Hydroxo‐bridged Tetranuclear CuII Complexes: {[Cu(bpy)(OH)]4Cl2}Cl2 · 6 H2O and {[Cu(phen)(OH)]4(H2O)2}]Cl4 · 4 H2O

The blue tetranuclear Cu^II complexes {[Cu(bpy)(OH)]₄Cl₂}Cl₂ · 6 H₂O ( 1 ) and {[Cu(phen)(OH)]₄(H₂O)₂}Cl₄ · 4 H₂O ( 2 ) were synthesized and characterized by single crystal X‐ray diffraction. ( 1 ): P 1 (no. 2), a = 9.240(1) Å, b = 10.366(2) Å, c = 12.973(2) Å, α = 85.76(1)°, β = 75.94(1)°, γ = 72.94(1)°, V = 1152.2(4) ų, Z = 1; ( 2 ): P 1 (no. 2), a = 9.770(3) Å, b = 10.118(3) Å, c = 14.258(4) Å, α = 83.72(2)°, β = 70.31(1)°, γ = 70.63(1)°, V = 1252.0(9) ų, Z = 1. The building units are centrosymmetric tetranuclear {[Cu(bpy)(OH)]₄Cl₂}²⁺ and {[Cu(phen)(OH)]₄(H₂O)₂}⁴⁺ complex cations formed by condensation of four elongated square pyramids CuN₂(OH)₂L^ap with the apical ligands L^ap = Cl, H₂O, OH. The resulting [Cu₄(μ₂‐OH)₂(μ₃‐OH)₂] core has the shape of a zigzag band of three Cu₂(OH)₂ squares. The cations exhibit intramolecular and intermolecular π‐π stacking interactions and the latter form 2D layers with the non‐bonded Cl^– anions and H₂O molecules in between (bond lengths: Cu–N = 1.995–2.038 Å; Cu–O = 1.927–1.982 Å; Cu–Cl^ap = 2.563; Cu–O^ap(OH) = 2.334–2.369 Å; Cu–O^ap(H₂O) = 2.256 Å). The Cu…Cu distances of about 2.93 Å do not indicate direct interactions, but the strongly reduced magnetic moment of about 2.74 B.M. corresponds with only two unpaired electrons per formula unit of 1 (1.37 B.M./Cu) and obviously results from intramolecular spin couplings (χ_m(T‐θ) = 0.933 cm³ · mol^–1 · K with θ = –0.7 K).     

Konformation und Vernetzung von (CuCN)6‐Ringen in polymeren Cyanocupraten(I) [Cu2(CN)3—] (n = 2, 3)

Conformation and Cross Linking of (CuCN)₆‐Rings in Polymeric Cyanocuprates(I) equation/tex2gif-stack-8.gif [Cu₂(CN)₃^—] (n = 2, 3) The alkaline‐tricyano‐dicuprates(I) Rbequation/tex2gif-stack-9.gif[Cu₂(CN)₃] · H₂O ( 1 ) and Csequation/tex2gif-stack-10.gif[Cu₂(CN)₃] · H₂O ( 2 ) were synthesized by hydrothermal reaction of CuCN and RbCN or CsCN. The dialkylammonium‐tricyano‐dicuprates(I) [NH₂(Me)₂]equation/tex2gif-stack-11.gif[Cu₂(CN)₃] ( 3 ), [NH₂(iPr)₂]equation/tex2gif-stack-12.gif[Cu₂(CN)₃] ( 4 ), [NH₂(Pr)₂]equation/tex2gif-stack-13.gif[Cu₂(CN)₃] ( 5 ) and [NH₂(secBu)₂]equation/tex2gif-stack-14.gif[Cu₂(CN)₃] ( 6 ) were obtained by the reaction of dimethylamine, diisopropylamine, dipropylamine or di‐sec‐butylamine with CuCN and NaCN in the presence of formic acid. The crystal structures of these compounds are built up by (CuCN)₆‐rings with varying conformations, which are connected to layers ( 1 ) or three‐dimensional zeolite type cyanocuprate(I) frameworks, depending on the size and shape of the cations ( 2 to 6 ). Crystal structure data: 1 , monoclinic, P2₁/c, a = 12.021(3)Å, b = 8.396(2)Å, c = 7.483(2)Å, β = 95.853(5)°, V = 751.4(3)ų, Z = 4, d_c = 2.728 gcm^—1, R₁ = 0.036; 2 , orthorhombic, Pbca, a = 8.760(2)Å, b = 6.781(2)Å, c = 27.113(5)Å, V = 1610.5(5)ų, Z = 8, d_c = 2.937 gcm^—1, R₁ = 0.028; 3 , orthorhombic, Pna2₁, a = 13.504(3)Å, b = 7.445(2)Å, c = 8.206(2)Å, V = 825.0(3)ų, Z = 4, d_c = 2.023 gcm^—1, R₁ = 0.022; 4 , orthorhombic, Pbca, a = 12.848(6)Å, b = 13.370(7)Å, c = 13.967(7)Å, V = 2399(2)ų, Z = 8, d_c = 1.702 gcm^—1, R₁ = 0.022; 5 , monoclinic, P2₁/n, a = 8.079(3)Å, b = 14.550(5)Å, c = 11.012(4)Å, β = 99.282(8)°, V = 1277.6(8)ų, Z = 4, d_c = 1.598 gcm^—1, R₁ = 0.039; 6 , monoclinic, P2₁/c, a = 16.215(4)Å, b = 13.977(4)Å, c = 14.176(4)Å, β = 114.555(5)°, V = 2922(2)ų, Z = 8, d_c = 1.525 gcm^—1, R₁ = 0.070.     

Hydrothermal Synthesis and X‐ray Crystal Structure of Four Inorganic‐Organic Hybrid Compounds in Vanadium /Copper Iodate Family

Four inorganic‐organic hybrid compounds with the formulae (1,10‐phen)(VO₂)(IO₃) ( 1 ), (2,2′‐bipy)(VO₂)(IO₃) ( 2 ), [Cu₃(2,2′‐bipy)₃Cl₃(IO₃)₂]·I_1.5 ( 3 ), and [Cu(2,2′‐bipy)(H₂O)(IO₃)₂]· (H₂O)₂ ( 4 ) are hydrothermally synthesized at 120 °C for 6 d and characterized by single‐crystal X‐ray diffraction. The use of two different bidentate organodiamine ligands 1,10‐phen and 2,2′‐bipy in the V/I/O system gives rise to compounds 1 and 2 , which crystallize in a monoclinic system with the space group C2/c, a = 17.8131(6) Å, b = 15.0470(7) Å, c = 12.9902(4) Å, β = 133.095(2)°, V = 2542.49(17) ų for 1 and space group P2₁/c, a = 13.3095(5) Å, b = 15.0993(8) Å, c = 13.0454(4) Å, β = 116.971(2)°, V = 2335.88(17) ų for 2 . The use of the bidentate organodiamine ligand 2,2′‐bipy in the Cu/I/O system gives rise to the variety in the structure of products 3 and 4 , which crystallize in a triclinic system with the same space group . a = 8.5143(2) Å, b = 10.4908(3) Å, c = 22.8420(6) Å, α = 93.769(10)°, β = 91.723(10)°, γ = 112.111(10)°, V = 1882.83(9) ų for 3 and a = 6.731(6) Å, b = 10.110(4) Å, c = 12.899(6) Å, α = 106.00(5)°, β = 95.45(4)°, γ = 107.69(6)°, V = 788.4(9) ų for 4 . The solid‐state structures of the compounds 1 and 2 have chains with repeat units of alternative corner sharing of [VO₄N₂] octahedra and [IO₃] pyramids. Compound 3 is a chain containing [IO₃] pyramids and [VO₄N] square pyramids and compound 4 consists of Cu(2,2′‐bipy)²⁺ linked by one water molecule and two [IO₃] pyramids. The thermal stabilities of the compounds are investigated.     

Cd3[B2P4O14(OH)4]: A 3D Open‐Framework Cadmium Borophosphate with Unique Twisted 8‐Ring Channels

Abstract. The cadmium borophosphate compound Cd₃[B₂P₄O₁₄(OH)₄] was synthesized under mild hydrothermal conditions. The crystal structure was determined by single‐crystal X‐ray diffraction [triclinic, space group P$\bar{1}$ (no. 2), a = 5.4362(11) Å, b = 8.2190(16) Å, c = 8.3918(17) Å, and α = 111.87(3)°, β = 104.63(3)°, γ = 90.73(3)°, V = 334.29(12) ų and Z = 1]. The 3D open framework of the title compound is constructed from BO₃(OH) tetrahedra and 2D layers along the [100] direction. The resulting framework contains twisted eight‐membered rings that form 1D channels.     

Four New Thioantimonates(III) with the General Formula [TM(tren)]Sb4S7 (TM = Mn,Fe, Co,Zn) with the Transition Metal as Part of a Thioantimonate(III) Network Synthesized under Solvothermal Conditions and Tuning of the Optical Band Gap by the Transition Metal Cation

Four new thioantimonate(III) compounds with the general formula [TM(tren)]Sb₄S₇, TM = Mn 1 , Fe 2 , Co 3 and Zn 4 , were synthesized under solvothermal conditions by reacting elemental TM, Sb and S in an aqueous solution of tren (tren = tris(2‐aminoethyl)amine). All compounds crystallize in the monoclinic space group P2₁/n with four formula units in the unit cell. Single crystal X‐ray analyses of 1 [a = 8.008(2), b = 10.626(2), c = 25.991(5) Å, β = 90.71(3)°, V = 2211.4(8) ų], 2 [a = 8.0030(2), b = 10.5619(2), c = 25.955(5) Å, β = 90.809(3)°, V = 2193.69(8) ų], 3 [a = 7.962(2), b = 10.541(2), c = 25.897(5) Å, β = 90.90(3)°, V = 2173.0(8) ų] and 4 [a = 7.978(2), b = 10.625(2), c = 25.901(5) Å, β = 90.75(3)°, V = 2195.2(8) ų] reveal that the compounds are isostructural. The [Sb₄S₇]^2‐ anions are composed of three SbS₃ trigonal pyramids and one SbS₄ unit as primary building units (PBU). The PBUs share common edges and corners to form semicubes (Sb₃S₄) which may be regarded as secondary building units (SBU). The SBUs and SbS₃ pyramids are joined in an alternating fashion yielding the equation/tex2gif-stack-1.gif[Sb₄S₇^‐] anionic chain which is directed along [100]. Weaker Sb‐S bonding interactions between neighbored chains lead to the formation of layers within the (001) plane which contain pockets that are occupied by the cations. The TM²⁺ ions are in a trigonal bipyramidal environment of four N atoms of the tren ligand and one S atom of the thioantimonate(III) anion. The optical band gaps depend on the TM²⁺ ion and amount to 3.11 eV for 1 , 2.04 eV for 2 , 2.45 eV for 3 , and 2.60 eV for 4 .     

NEW THREE DIMENSIONAL [Cd(CN)2]n FRAMEWORK FORMED WITH CADMIUM CYANIDE AND Cd(CN)2·(18-CROWN-6): CRYSTAL STRUCTURE OF [Cd(CN)2]·1/2[Cd(CN)2 (18-CROWN-6)]·3/2EtOH+

Abstract

The cadmium complex Cd(CN)₂·(18-crown-6) (1) was synthesized and its structure was determined by X-ray crystallography. The cadmium ion in 1 has a hexagonal bipyramidal geometry containing six equatorial oxygen atoms from the crown ether and two axial CN ligands. The NC-Cd-CN ‘rod’ is perfectly linear with an end-to-end distance of 6.509 (12) Å. When 1 was allowed to diffuse into a cadmium cyanide solution, the infinite coordination complex [Cd(CN)₂]·1/2[(Cd(CN)₂·(18-crown-6)]·3/2EtOH (2) was obtained in which the cadmium macrocycle 1 was trapped in a 10-faced-cage formed by the [Cd(CN)₂]n framework. The terminal nitrogen atoms of 1 bind two Cd centers across the cage. The trapped Cd(CN)₂·(18-crown-6) has a significantly bent NC-Cd-CN unit and the crown ether ligand disordered over two orientations. The [Cd(CN)₂]_n framework viewed down the c axis shows two types of channels, one octagonal and one tetragonal, which are filled with Cd(CN)₂·(18-crown-6) and ethanol molecules, respectively. Crystallographic data of 1: trigonal, space group R·3 (hexagonal axis), a = 11.757 (1), c = 12.105 (1) Å, V = 1449.1 (2) ų, Z = 3, R = 0.0566, R_w = 0.0674 for 827 unique reflections (I>3σ(I)). Crystallographic data of 2: orthorhombic, Pbcn, a = 16.632 (1), b = 17.391 (3), c = 15.685 (2) Å, V = 4536.8 (9) ų, Z = 8. R = 0.0486, R_w = 0.0492 for 929 unique reflections (I>3σ(I)).     

Ein Beitrag zu Rhenium(II)‐, Osmium(II)‐ und Technetium(II)‐Thionitrosylkomplexen vom Typ [M(NS)Cl4py]—: Darstellung,Strukturen und EPR‐Spektren

A Contribution to Rhenium(II)‐, Osmium(II)‐, and Technetium(II)‐Thionitrosyl‐Complexes: Preparation, Structures, and EPR‐Spectra The reaction of [Re^VINCl₄]^— and [Os^VINCl₄]^— with S₂Cl₂ leads to the formation of the thionitrosyl complexes [M^II(NS)Cl₄]^— (M = Re, Os) which could not be isolated as pure compounds. Addition of pyridine to the reaction mixture results in the formation of the stable compounds trans‐(Ph₄P)[Os^II(NS)Cl₄py], trans‐(Hpy)[Os^II(NS)Cl₄py], trans‐(Ph₄P)[Re^II(NS)Cl₄py], and cis‐(Ph₄P)[Re^II(NS)Cl₄py]. The crystal structure analyses show for trans‐(Ph₄P)[Os^II(NS)Cl₄py] (monoclinic, P2₁/n, a = 12.430(3)Å, b = 18.320(4)Å, c = 15.000(3)Å, β = 114.20(3)°, Z = 4), trans‐(Hpy)[Os^II(NS)Cl₄py] (monoclinic, P2₁/n, a = 7.689(1)Å, b = 10.202(2)Å, c = 20.485(5)Å, β = 92.878(4)°, Z = 4), trans‐(Ph₄P)[Re^II(NS)Cl₄py] (triclinic, P1¯, a = 9.331(5)Å, b = 12.068(5)Å, c = 15.411(5)Å, α = 105.25(1)°, β = 90.23(1)°, γ = 91.62(1)°, Z = 2), and cis‐(Ph₄P)[Re^II(NS)Cl₄py] (monoclinic, P2₁/c, a = 10.361(1)Å, b = 16.091(2)Å, c = 17.835(2)Å, β = 90.524(2)°, Z = 4) M‐N‐S angles in the range 168‐175°. This indicates a nearly linear coordination of the NS ligand. The metal atom is octahedrally coordinated in all cases. The rhenium(II) thionitrosyl complexes (5d⁵ “low‐spin” configuration, S = 1/2) are studied by EPR in the temperature range 295 > T > 130 K. In addition to the detection of the complexes formed during the reaction of [Re^VINCl₄]^— with S₂Cl₂ EPR investigations on diamagnetically diluted powders and single crystals of the system (Ph₄P)[Re^II/Os^II(NS)Cl₄py] are reported. The ^{185, 187}Re hyperfine parameters are used to get information about the spin‐density distribution of the unpaired electron in the complexes under study. [Tc^VINCl₄]^— reacts with S₂Cl₂ under formation of [Tc^II(NS)Cl₄]^— which is not stable and decomposes under S₈ elimination and rebuilding of [Tc^VINCl₄]^— as found by EPR monitoring of the reaction.     

SYNTHESIS OF A DINUCLEAR YLID COMPLEX DERIVED FROM P(OPh)3: CRYSTAL STRUCTURES OF [Cp2Fe2(CO)2(μ-CO) (μ-CHP(OPh)3)+][BF4 −] AND [Cp2Fe2(CO)2 (μ-CO)(μ-CHPPh3)+][BF4 −]

Abstract

[Cp₂Fe₂(CO)₂(μ-CO)(μ-CHP(OPh)₃)⁺][BF^? ₄] crystallizes in the centrosymmetric monoclinic space group P2₁/n with a = 12.553(7) Å, b = 16.572(11) Å, c = 15.112(8) Å, β = 100.00(4)°, V = 3096(3) ų and D(calcd.) = 1.579 g/cm³ for Z = 4. The structure was refined to R(F) = 5.83% for 1972 reflections above 4σ(F). The cation contains two CpFe(CO) fragments linked via an iron—iron bond (Fe(1)—Fe(2) = 2.544(3)Å), a bridging carbonyl ligand (Fe(1)—C(4) = 1.918(1) Å, Fe(2)—C(4) = 1.946(12)Å) and a bridging CHP(OPh)₃ ligand (Fe(1)—C(1) = 1.980(9)Å, Fe(2)—C(1) = 1.989(8)Å). Distances within the μ-CHP(OPh)₃ moiety include a rather short carbon—phosphorus bond [C(1)—P(1) = 1.680(10)Å] and P—O bond lengths of 1.550(7)–1.579(6)Å. The crystal is stabilized by a network of F…H—C interactions involving the BF^? ₄ anion.

[Cp₂Fe₂(CO)₂(μ-CO)(μ-CHPPh₃)⁺][BF^? ₄], which differs from the previous compound only in having a μ-CHPPh₃ (rather than μ-CHP(OPh)₃) ligand, crystallizes in the centrosymmetric monoclinic space group P2₁/c with a = 11.248(5)Å, b = 13.855(5)Å, c = 18.920(7)Å, β = 96.25(3)°, V = 2931(2)ų and D(calcd.) = 1.559 g/cm³ for Z = 4. This structure was refined to R(F) = 4.66% for 1985 reflections above 4σ(F). Bond lengths within the dinuclear cation here include Fe(1)-Fe(2) = 2.529(2)Å, Fe(1)—C(3) = 1.904(9) Å and Fe(2)—C(3) = 1.911(8) Å (for the bridging CO ligand) and Fe(1)—C(1P) = 1.995(6) Å and Fe(2)—C(1P) = 1.981(7) Å (for the bridging CHPPh₃ ligand). Distances within the μ-CHPPh₃ ligand include a longer carbon—phosphorus bond [C(1P)—P(1) = 1.768(6)Å] and P(1)—C(phenyl) = 1.797(7)–1.815(8) Å.     

Cadmium nitrate coordination polymers with substituted pyridazino[4,5‐d]pyridazines

catena‐Poly[[aquabis(nitrato‐κ²O,O′)cadmium(II)]‐μ‐1,2,3,6,7,8‐hexa­hydro­cinnolino[5,4,3‐cde]cinnoline‐κN¹:κN⁶], [Cd(NO₃)₂(C₁₂H₁₂N₄)(H₂O)]_n, (I), and catena‐poly[[[bis(nitrato‐κ²O,O′)cadmium(II)]‐μ‐2,2,7,7‐tetra­methyl‐1,2,3,6,7,8‐hexahydro­cinnolino[5,4,3‐cde]cinnoline‐κN¹:κN⁶] chloro­form solvate], {[Cd(NO₃)₂(C₁₂H₁₂N₄)]·CHCl₃}_n, (II), are the first structurally examined cadmium–pyridazine coordination compounds. They possess one‐dimensional polymeric structures supported by the bidentate bridging function of the cinnolino[5,4,3‐cde]cinnoline ligands, which lie about inversion centres. The Cd atoms are seven‐coordinated in (I) and six‐coordinated in (II), involving two bidentate nitrate groups [Cd—O = 2.229 (2)–2.657 (2) Å], two N atoms of the cinnoline ligands [Cd—N = 2.252 (2)–2.425 (2) Å], and, additionally, a water O atom in (I) [Cd—O = 2.284 (2) Å]. In (I), the coordinated organic and aqua ligands form an intra­molecular O—H⋯N hydrogen bond [O⋯N = 2.730 (3) Å].     

Transition Metal Halide Salts and Complexes of 2-Aminopyrimidine: Cobalt(II) and Nickel(II) compounds,Crystal Structures of Bis(2-Aminopyrimidinium)MX4 [M = Co,Ni; X = Cl,Br] and 2-Aminopyrimidinium(+2) [NiBr2(H2O)4]Br2

The reaction of MX₂ (M = Co(II), Ni(II); X = Cl, Br) with 2-aminopyrimidine in aqueous acid yields compounds [(2-apmH)₂MX₄], (2-apmH)₂[MX₄], or (2-apmH₂) [MX₂(H₂O)₄]X₂ (2-apmH = 2-aminopyrimidinium; 2-apmH₂ = 2-aminopyrimidinium(2+)). All compounds have been characterized by single crystal X-ray diffraction. The compounds [(2-apmH)₂MX₄] with M = Co, X = Cl (1); M = Ni, X = Cl (3); and M = Ni, X = Br (4) are isomorphous and crystallize as nearly square planar MX₄ units with the 2-apmH cations coordinated in the axial sites through the unprotonated ring nitrogen. (2-ApmH)₂[CoBr₄] (2) crystallizes as the salt with a nearly tetrahedral CuBr₄ ^2- anion. (2-ApmH₂)[NiBr₂(H₂O)₄]Br₂ (5) forms as a cocrystal of the neutral, six-coordinate nickel complex and (2-ampH₂)Br₂, stabilized by extensive hydrogen bonding. Crystal data (1): monoclinic, P2₁/c, a = 7.540(4), b = 12.954(4), c = 7.277(3) Å, β = 110.09(6), V = 667.4(5) ų, Z = 2, D_calc = 1.955 Mg/m³, μ = 2.079 mm^-1, R = 0.0501 for [|I|≥2(I)]. For (2): triclinic, P-1, a = 7.720(2), b = 7.916(2), c = 14.797(3) Å, α = 97.264(3), β = 104.788(3), γ = 105.171(3)°, V = 825.3(3) ų, Z = 2, D_calc = 2.296 Mg/m³, μ = 10.715 mm^-1, R = 0.0308 for [|I|≥2(I)]. For (3): monoclinic, P2₁/c, a = 7.595(3), b = 12.891(4), c = 7.204(3) Å, β = 111.07(3)°, V = 658.2 ų, Z = 2, D_calc = 1.982 Mg/m³, μ = 2.279 mm^-1, R = 0.0552 for [|I|≥2(I)]. For (4): monoclinic, P2₁/c, a = 7.840(2), b = 13.358(4), c = 7.518(2) Å, β = 110.923(3)°, V = 938.6(3) ų, Z = 2, D_calc = 2.577 Mg/m³, μ = 12.18 mm^-1, R = 0.0280 for [|I|≥2(I)]. For (5): orthorhombic, Pnma, a = 16.776(6), b = 11.943(4), c = 7.079(3) Å, V = 1418.2(9) ų, Z = 4, D_calc = 2.564 Mg/m³, μ = 12.639 mm^-1, R = 0.0381 for [|I|≥2σ(I)].