[Cu(men)2(BF4)2] (men = N-methyl-1,2-diaminoethane): Preparation, crystal structure, spectroscopic and magnetic properties

Single crystals of [Cu(men)₂(BF₄)₂] (men = N-methyl-1,2-diaminoethane) (1) were isolated from an aqueous-ethanolic system Cu²⁺-men-BF₄⁻. The crystal structure of 1 consists of [Cu(men)₂(BF₄)₂] molecules. Copper ion exhibits usual distorted octahedral coordination; there are two coordinated men ligands in the equatorial plane with Cu-N bonds of 2.0451(12) and 2.0035(12) Å, while the axial positions are occupied by fluorine atoms from BF₄⁻ anions with Cu-F bond of 2.5091(11) Å. The packing of the [Cu(men)₂(BF₄)₂] molecules is governed by N-H?F type hydrogen bonds. The measured ESR spectrum corroborated the presence of Jahn-Teller anisotropy of Cu(II) with g_|| = 2.20 and g_⊥ = 2.06. The magnetic studies in the temperature range 300-2 K reveal that 1 follows the Curie-Weiss law with parameters g = 2.1612(1) and θ = −0.233(1) K suggesting the presence of weak antiferomagnetic interactions.     

Structural and spectroscopic properties of Hexamethylenetetramine cobalt(II) complex: [Co(NCS)2(hmt)2(H2O)2][Co(NCS)2(H2O)4] (H2O)

Synthesis, structure, spectroscopy and thermal properties of complex [Co(NCS)₂(hmt)₂(H₂O)₂][Co(NCS)₂(H₂O)₄] (H₂O) (I), assembled by hexamethylenetetramine and octahedral Co(II) metal ions, are reported. Crystal data for I: F_w 387.34, a=9.020(8), b=12.887(9), c=7.95(1) Å, =96.73(4), β=115.36(5), γ=94.16(4)°, V=820(1) Å³, Z=2, space group=P−1, T=173 K, λ(Mo-K)=0.71070 Å, ρ_calc=1.718567 g cm⁻³, μ=17.44 cm⁻¹, R=0.088, R_w=0.148. An interesting two-dimensional network is assembled via hydrogen bonds through coordinated and free water molecules. The d–d transition energy levels of Co(II) ion are determined by UV–vis spectroscopy and calculated by ligand field theory. The calculated results agree well with experiment ones.     

Stabilisation of heterobimetallic networks by crown ethers and hydrogen-bonding in [Ni(H2O)6][Cu3Cl8(H2O)2] · (15-crown-5)2 · 2H2O: Structure and magnetism

[Ni(H₂O)₆][Cu₃Cl₈(H₂O)₂] · (15-crown-5)₂ · 2H₂O can be conveniently prepared by the interaction of NiCl₂ · 6H₂O, CuCl₂ · 2H₂O and 15-crown-5 in water. The X-ray crystal structure reveals an ionic complex involved in a hydrogen-bonded two dimensional network with the [Ni(H₂O)₆]²⁺ and [Cu₃Cl₈(H₂O)₂]²⁻ ions sandwiched between the 15-crown-5 macrocycles. The magnetic susceptibility data (4–300 K) and magnetisation isotherms (2–5.5 K; 0–5 T) are best interpreted in terms of intra-trimer ferromagnetic coupling within the [Cu₃Cl₈(H₂O)₂]²⁻ moieties, with J ∼ 6 cm⁻¹, and antiferromagnetic coupling between the trimers, the latter mediated by H-bonding pathways. Comparisons are made to other reported quaternary ammonium salts of [Cu₃Cl₈]²⁻ and [Cu₃Cl₁₂]⁶⁻, most of which display structures that involve close stacking of such Cu(II) trimers, rather than being of the present isolated, albeit H-bonded, types.     

Structure and bonding in a series of cyano complexes: RuCp(PPh3) 2CN, [RuCp(PPh3) 2(CNH)]CF3SO3, and H-bridged [Ru2(Cp) 2(PPh3) 4CNHNC]CF3SO3

The three title cyanoruthenium complexes have been characterized by means of X-ray diffraction analysis, IR and NMR solution spectroscopies, as well as extended Hückel molecular orbital calculations examining the properties of the cyanide fragment changing with complexation and with the co-ligands Cp and PPh₃. Explanations are given for crystallographic results of the C-N bond shortening upon complexation, the supershort (2.573 Å) bond length of N(H) N in the bridged complex, as well as the Ru-C-N and C-N-H-N-C bendings. Although the crystallographically found asymmetry of coordinated Cp is not significant, the MO calculations suggest a distorted endocyclic bond-length pattern indicative of the relative importance of σ and π bonding in the metalcyclopentadienyl interactions.     

Ferromagnetic exchange coupling in phosphonato-bridged dinuclear copper(II) compound with monoethyl (pyridyn-2-ylmethyl)phosphonate ligand (2-mpmpe): Cu2(2-mpmpe)2(H2O)2(NO3)2

The interaction of diethyl (pyridyn-2-ylmethyl)phosphonate (2-pmpe) with Cu(NO₃)₂ · 6H₂O leads to a partial hydrolysis of the starting ligand and formation of the compound of the formula Cu₂(2-mpmpe)₂(H₂O)₂(NO₃)₂, where 2-mpmpe = monoethyl (pyridyn-2-ylmethyl)phosphonate. The crystal and molecular structure of a copper(II) compound was determined by single X-ray diffraction method. Its structure consists of five-coordinated in distorted square planar geometry (CuNO₄ chromophore) copper(II) ions doubly bridged by OPO from phosphonate. The Cu?Cu distance is 4.69 Å. The crystal packing is determined by the interdinuclear hydrogen bond system, which leads to a three-dimensional (3D) H-bonds network. The compound was characterized by infrared, ligand field, EPR spectroscopy, and magnetic studies. The magnetic properties of the title compound investigated over the 1.8–300 K, revealed the occurrence of a weak ferromagnetic coupling through phosphonate bridge (J = 1.86 cm⁻¹) and interdimer superexchange coupling through H-bond network (zJ′ = −0.17 cm⁻¹). Spectroscopic and magnetic properties are presented in the light of crystal structure.     

Synthesis, structural characterization and reactivity of the amino borane 1-(NPh2)-2-[B(C6F5)2]C6H4

The bright red title compound 1 was synthesized from (2-lithiophenyl)diphenylamine and bis(pentafluorophenyl)boron chloride. Its reactions with small acids like H₂O and HCl proceeded easily giving zwitterionic compounds. For 1 and its water adduct 2 the crystal structures were determined, the latter featuring an ammonium borate structure containing a short intramolecular hydrogen bond bridge. Treatment of 1 with Jutzi's acid, [H(OEt₂)₂][B(C₆F₅)₄], did not result in protonation of the nitrogen, but reaction of 1 with LiH in the presence of 12-crown-4, led to the isolation of the aminoborate [1-(Ph₂N)-2-{B(H)(C₆F₅)₂}C₆H₄][Li(12-crown-4)] (3). Borohydride 3 reacted with Jutzi's acid to regenerate 1 and liberate hydrogen.     

Synthesis and coordinating properties of the facultative Sb2O- and As2O-donor ligands O{(CH2)2ER2}2 (E = Sb or As; R = Ph or Me)

The new mixed Sb₂O-donor ligands O{(CH₂)₂SbR₂}₂ (R = Ph, 1; R = Me, 2) with flexible backbones have been prepared in good yields as air-sensitive oils from reaction of NaSbR₂ with 0.5 mol equivalents of O(CH₂CH₂Br)₂ in thf solution. The As₂O-donor analogues, O{(CH₂)₂AsR₂}₂ (R = Ph, 3; R = Me, 4) were obtained similarly from LiAsPh₂ or NaAsMe₂, respectively and O(CH₂CH₂Br)₂, although ligand 4 appears to be considerably less stable with respect to C-O bond fission under some conditions than the other ligands. Using O(CH₂CH₂Cl)₂ leads only to partial substitution by the SbPh₂⁻ or AsPh₂⁻ nucleophile. These ligands behave as bidentate chelating Sb₂- or As₂-donors in the distorted tetrahedral [M(L-L)₂]BF₄ (M = Cu or Ag; L-L = 1-4) on the basis of solution ¹H and ⁶³Cu NMR spectroscopic studies, mass spectrometry and microanalyses. Crystal structures of three representative examples with Cu(I) and Ag(I) confirm the distorted tetrahedral Sb₄ or As₄ coordination at the metal and allow comparisons of geometric parameters. The crystallographic identification of an unexpected Cu(I)-Cu(I) complex, [Cu₂{Me₂As(CH₂)₂OH}₃](BF₄)₂, obtained as a by-product via C-O bond fission within ligand 4 is also reported. The distorted octahedral [RhCl₂(L-L)₂]Cl and the distorted square planar cis-[PtCl₂(L-L)] (L-L = 1 or 2) are also described. The ether O atoms are not involved in coordination to the metal ion in any of the late transition metal complexes isolated.     

Structural, spectral and thermal studies of substituted N-(2-pyridyl)-N′-phenylthioureas

N-2-(3-picolyl)-N′-phenylthiourea, 3PicTuPh, monoclinic, P2₁/n, a=7.617(2) b=7.197(5), c=22.889(5) Å, β=94.63(4)°, V=1250.7(1) Å³ and Z=4; N-2-(4-picolyl)-N′-phenylthiourea, 4PicTuPh, triclinic, P-1, a=7.3960(5), b=7.9660(12), c=21.600(3) Å, α=86.401(4), β=84.899(8), γ=77.769(8)°, V=1237.5(3) Å³ and Z=4; N-2-(5-picolyl)-N′-phenylthiourea, 5PicTuPh, monoclinic, P2₁/c, a=14.201(1), b=4.905(3), c=17.689(3) Å, β=91.38(1)°, V=1231.8(7) Å³ and Z=4; N-2-(6-picolyl)-N′-phenylthiourea, 6PicTuPh, monoclinic, C2/c2, a=14.713(1), b=9.367(1), c=18.227(1) Å, β=92.88(1)°, V=2515.5(1) Å³ and Z=8 and N-2-(4,6-lutidyl)-N′-phenylthiourea, 4,6LutTuPh, monoclinic, C2/c, a=11.107(2), b=11.793(2), c=20.084(4) Å, β=96.10(3)°, V=2616(1) Å³ and Z=8. Intramolecular hydrogen bonding between N′H and the pyridyl nitrogen and intermolecular hydrogen bonding involving the thione sulfur are affected by substitution of the pyridine ring, as is the planarity of the molecule. ¹H NMR studies in CDCl₃ show the NH′ hydrogen resonance considerably downfield from other resonances in the spectrum for each thiourea.     

A crystallographic and DFT study on Vaska-type trans-[Rh(CO)Cl(PR3)2] complexes containing flexible ligands: The molecular structure of trans-[Rh(CO)Cl{P(OC6H5)3}2]

An investigation into the effect of the flexibility of substituents on the disorder of the Cl-Rh-CO moiety in Vaska-type trans-[Rh(CO)Cl(PR₃)₂] complexes is presented. The influence of the packing of the complexes with PR₃ = P(CH₂C₆H₅)₃, P(OC₆H₅)₃, P(O-2-MeC₆H₄)₃ and P(O-2,6-Me₂C₆H₃)₃ was evaluated by comparing the X-ray structures with the results of DFT calculations on these complexes. Reasonable agreement between the calculated and molecular structures was found. A good agreement, however, was found between the calculated and crystallographic structures when comparing the coordination polyhedron around the Rh atom. The main difference between the calculated and solid state structures appeared to be in the orientation of the phenyl groups of the P-donor ligands.     

Tetrakis(triphenylphosphine oxide) complexes of the lanthanide nitrates; synthesis, characterisation and crystal structures of [La(Ph3PO)4(NO3)3]·Me2CO and [Lu(Ph3PO)4(NO3)2]NO3

The reaction of Ln(NO₃)₃·6H₂O (Ln=La, Ce, Pr or Nd) with a sixfold excess of Ph₃PO in acetone formed [Ln(Ph₃PO)₄(NO₃)₃]·Me₂CO. The crystal structure of the La complex shows a nine-coordinate metal centre with four phosphine oxides, two bidentate and one monodentate nitrate groups, and PXRD studies show the same structure is present in the other three complexes. In CH₂Cl₂ or Me₂CO solutions, ³¹P NMR studies show that the complexes are essentially completely decomposed into [Ln(Ph₃PO)₃(NO₃)₃] and Ph₃PO. Similar reactions in ethanol gave [Ln(Ph₃PO)₃(NO₃)₃] only. In contrast for Ln=Sm, Eu or Gd, only the [Ln(Ph₃PO)₃(NO₃)₃] are formed from either acetone or ethanol solutions. For the later lanthanides Ln=Tb–Lu, acetone solutions of Ln(NO₃)₃·6H₂O and Ph₃PO gave [Ln(Ph₃PO)₃(NO₃)₃] only, even with a large excess of Ph₃PO, but from cold ethanol [Ln(Ph₃PO)₄(NO₃)₂]NO₃ (Ln=Tb, Ho–Lu) were obtained. The structure of [Lu(Ph₃PO)₄(NO₃)₂]NO₃ shows an eight-coordinate metal centre with four phosphine oxides and two bidentate nitrate groups. In solution in CH₂Cl₂ or Me₂CO the tetrakis-complexes show varying amounts of decomposition into mixtures of [Ln(Ph₃PO)₃(NO₃)₃], [Ln(Ph₃PO)₄(NO₃)₂]NO₃ and Ph₃PO as judged by ³¹P{¹H} NMR spectroscopy. The [Ln(Ph₃PO)₃(NO₃)₃] also partially decompose in solution for Ln=Dy–Lu, forming some tetrakis(phosphine oxide) species.     

Synthesis, characterization, protonation studies and X-ray crystal structure of ReH5(PPh3)2(PTA) (PTA = 1,3,5-triaza-7-phosphaadamantane)

The novel rhenium pentahydride complex [ReH₅(PPh₃)₂(PTA)] (2) was synthesized by dihydrogen replacement from the reaction of [ReH₇(PPh₃)₂] with PTA in refluxing THF. Variable temperature NMR studies indicate that 2 is a classic polyhydride (T_1(min) = 133 ms). This result agrees with the structure of 2, determined by X-ray crystallography at low temperature. The compound shows high conformational rigidity which allows for the investigation of the various hydride-exchanging processes by NMR methods. Reactions of 2 with equimolecular amounts of either HFIP or HBF₄ · Et₂O at 183 K afford [ReH₅(PPh₃)₂{PTA(H)}]⁺ (3) via protonation of one of the nitrogen atoms on the PTA ligand. When 5 equivalents of HBF₄ · Et₂O are used, additional protonation of one hydride ligand takes place to generate the thermally unstable dication [ReH₄(η²-H₂)(PPh₃)₂{PTA(H)}]²⁺ (4), as confirmed by ¹H NMR and T₁ analysis. IR monitoring of the reaction between 2 and CF₃COOD at low temperature shows the formation of the hydrogen bonded complex [ReH₅(PPh₃)₂{PTA?DOC(O)CF₃}] (5) and of the ionic pair [ReH₅(PPh₃)₂{PTA(D)?OC(O)CF₃}] (6) preceding the proton transfer step leading to 3.     

Supramolecular 2D structures in [M(NCS)2(bpe)2(H2O)2] (M = Mn, Fe) systems connected by hydrogen bonds

Here we report the synthesis and characterization by X-ray diffraction, FTIR, UV-Vis and EPR spectroscopies, and the magnetic measurements of two new compounds: [Mn(NCS)₂(bpe)₂(H₂O)₂] (1) and [Fe(NCS)₂(bpe)₂(H₂O)₂] (2) (bpe = 1,2-bis(4-pyridyl)ethylene). Single-crystal structure analyses reveals discrete octahedral metal units that are assembled into 2D sheets through O-Hw?N(bpe) and O-Hw?S(thiocyanate) hydrogen bonds. The intermetallic M?M distances are 6.90 and 6.87 Å for 1 and 2, respectively. Supramolecular architectures are obtained by connections through H-bonds. Slight interactions are observed for compound 2.     

Reactions of the dichloroboryl complex of osmium, Os(BCl2)Cl(CO)(PPh3)2, with water, alcohols, and amines: Crystal structures of Os[B(OH)2]Cl(CO)(PPh3)2, Os[B(OEt)2]Cl(CO)(PPh3)2, and

Two novel N,N′-dialkylimidazolium thiocyanate-cadmium complexes [(R₂Im)₂][Cd₂(SCN)₆] for R=Me (3), and cyclohexyl (4) have been synthesized and characterized by single-crystal X-ray diffraction. Compound 3 crystallizes in the monoclinic unit cell dimensions of 17.468(3), 7.7273(12), 10.6750(16) Å, 104.833(2)°, and space group C2 with two [(Me₂Im)₂] [Cd₂(SCN)₆] per unit cell. The two cadmium atoms in 3 are octahedrally coordinated in 4N2S and 2N4S coordination environment, and linking into one-dimensional zigzag chains. Compound 4 belongs to the monoclinic space group Cc with unit cell of dimensions 13.3049(12), 17.5550(16), 20.8012(19) Å, 101.494(2)°, and four [(Cy₂Im)₂][Cd₂(SCN)₆]·C₃H₆O per unit cell. The cadmium atoms in 4 are all 3N3S hexa-coordinated with six bridging SCN⁻ ions in an fac configuration and form infinite zigzag polymeric chains. The infinite chains in 3 form an approximate hexagonal array, making triangular channels which are occupied by N,N′-dimethylimidazolium ions, whereas the chains in 4 form layered structure, and the layers are stacked perpendicularly with respect to the orientation of the infinite anionic chains alternatively. N,N′-dicyclohexylimidazolium cations and solvent molecules fill in between layers.     

Inorganic-Organic Hybrid Materials: Synthesis and X-Ray Structure of N,N′-Dimethylimidazolium Salts [(Me2Im)2][Cd2(SCN)6] and N,N′-Dicyclohexylimidazolium [(Cy2Im)2][Cd2(SCN)6]·C3H6O

Two novel N,N′-dialkylimidazolium thiocyanate-cadmium complexes [(R₂Im)₂][Cd₂(SCN)₆] for R=Me (3), and cyclohexyl (4) have been synthesized and characterized by single-crystal X-ray diffraction. Compound 3 crystallizes in the monoclinic unit cell dimensions of 17.468(3), 7.7273(12), 10.6750(16) Å, 104.833(2)°, and space group C2 with two [(Me₂Im)₂] [Cd₂(SCN)₆] per unit cell. The two cadmium atoms in 3 are octahedrally coordinated in 4N2S and 2N4S coordination environment, and linking into one-dimensional zigzag chains. Compound 4 belongs to the monoclinic space group Cc with unit cell of dimensions 13.3049(12), 17.5550(16), 20.8012(19) Å, 101.494(2)°, and four [(Cy₂Im)₂][Cd₂(SCN)₆]·C₃H₆O per unit cell. The cadmium atoms in 4 are all 3N3S hexa-coordinated with six bridging SCN⁻ ions in an fac configuration and form infinite zigzag polymeric chains. The infinite chains in 3 form an approximate hexagonal array, making triangular channels which are occupied by N,N′-dimethylimidazolium ions, whereas the chains in 4 form layered structure, and the layers are stacked perpendicularly with respect to the orientation of the infinite anionic chains alternatively. N,N′-dicyclohexylimidazolium cations and solvent molecules fill in between layers.     

Hydridic reactivity of W(CO)(H)(NO)(PMe3)3 - Dihydrogen bonding and H2 formation with protic donors

The hydridic reactivity of the complex W(CO)(H)(NO)(PMe₃)₃ (1) was investigated applying a variety of protic donors. Formation of organyloxide complexes W(CO)(NO)(PMe₃)₃(OR) (R = C₆H₅ (2), 3,4,5-Me₃C₆H₂ (3), CF₃CH₂ (4), C₆H₅CH₂ (5), Me (6) and iPr (7)) and H₂ evolution was observed. The reactions of 1 accelerated with increasing acidity of the protic donor: Me₂CHOH (pK_a = 17) < MeOH (pK_a = 15.5) < C₆H₅CH₂OH (pK_a = 15) < CF₃CH₂OH (pK_a = 12.4) < C₆H₂Me₃OH (pK_a = 10.6) < C₆H₅OH (pK_a = 10).Regioselective hydrogen bonding of 1 was probed with two of the protic donors furnishing equilibrium formation of the dihydrogen bonded complexes ROH···HW(CO)(NO)(PMe₃)₃ (R = 3,4,5-Me₃C₆H_2,3a and iPr, 7a) and the O_NO hydrogen bonded species ROH···ONW(CO)(H)(PMe₃)₃ (R = C₆H₂Me_3,3b and iPr, 7b) which were studied in hexane and d₈-toluene solutions using variable temperature IR and NMR spectroscopy. Quantitative IR experiments at low temperatures using 3,4,5-trimethylphenol (TMP) confirmed the two types of competitive equilibria: dihydrogen bonding to give 3a (ΔH₁ = −5.8 ± 0.4 kcal/mol and ΔS₁ = −15.3 ± 1.4 e.u.) and hydrogen bonding to give 3b (ΔH₂ = −2.8 ± 0.1 kcal/mol and ΔS₂ = −5.8 ± 0.3 e.u.). Additional data for the hydrogen bonded complexes 3a,b and 7a,b were determined via NMR titrations in d₈-toluene from the equilibrium constants K_(Δδ) and K_(ΔR1) measuring either changes in the chemical shifts of H_W(_Δδ) or the excess relaxation rates of H_W (ΔR₁) (3a,b: ΔH_(Δδ) = −0.8 ± 0.1 kcal/mol; ΔS_(Δδ) = −1.4 ± 0.3 e.u. and ΔH_(ΔR1) = −5.8 ± 0.4 kcal/mol; ΔS_(ΔR1) = −22.9 ± 1.9 e.u) (7a,b: ΔH_(Δδ) = −2.3 ± 0.2 kcal/mol; ΔS_(Δδ) = −11.7 ± 0.9 e.u. and ΔH_(ΔR1) = −2.9 ± 0.2 kcal/mol; ΔS_(ΔR1) = −14.6 ± 1.0 e.u). Dihydrogen bonding distances of 1.9 Å and 2.1 Å were derived for 3a and 7a from the NMR excess relaxation rate measurements of H_W in d₈-toluene. An X-ray diffraction study was carried out on compound 2.     

Influence of coordination on N-H X hydrogen bonds. Part II. Zn(NH3)2Br2 and Ni(NH3)2X2 (X is Cl and Br)

Microcrystalline samples of Zn(NH₃)₂Br₂ and Ni(NH₃)₂X₂ (X is Cl⁻ and Br⁻) have been investigated from 100 to 293 K using X-ray diffraction and IR spectroscopy measurements (range 400–4000 cm⁻) performed with isotopically dilute (5% deuterated) samples. Values of Δν(ND)/ΔT for all compounds hint at the existence of hydrogen bonds. Zn(NH₃)₂Br₂ shows The dynamics of ammonia molecules even at 100 K, and no indications are apparent that dynamic disorder of ammonia molecules takes place in Ni(NH₃)₂X₂ (X is Cl⁻ and Br⁻). A comparison between octahedrally coordinated ammoniates [Ni(NH₃)₆]Br₂, Ni(NH₃)₂Br₂ and [Zn(NH₃)₆]Br₂ with tetrahedrally coordinated ones [Zn(NH₃)₂Br₂] leads to the conclusion that the lower coordination number increases the strength of the hydrogen bonds. Because this effect is small, it is not possible to separate the influence of the type of coordinating ions for one coordination number from the influence of the coordination number itself.     

Structural and energetic aspects of hydrogen bonding and proton transfer to ReH2(CO)(NO)(PR3)2 and ReHCl(CO)(NO)(PMe3)2 by IR and X-ray studies

The interaction of rhenium hydrides ReHX(CO)(NO)(PR₃)₂ 1 (X=H, R=Me (a), Et (b), iPr (c); X=Cl, R=Me (d)) with a series of proton donors (indole, phenols, fluorinated alcohols, trifluoroacetic acid) was studied by variable temperature IR spectroscopy. The conditions governing the hydrogen bonding ReHHX in solution and in the solid state (IR, X-ray) were elucidated. Spectroscopic and thermodynamic characteristics (−ΔH=2.3–6.1 kcal mol⁻¹) of these hydrogen bonded complexes were obtained. IR spectral evidence that hydrogen bonding with hydride atom precedes proton transfer and the dihydrogen complex formation was found. Hydrogen bonded complex of ReH₂(CO)(NO)(PMe₃)₂ with indole (2a–indole) and organyloxy-complex ReH(OC₆H₄NO₂)(CO)(NO)(PMe₃)₂ (5a) were characterized by single-crystal X-ray diffraction. A short NHHRe (1.79(5) Å) distance was found in the 2a–indole complex, where the indole molecule lies in the plane of the Re(NO)(CO) fragment (with dihedral angle between the planes 0.01°).     

Synthesis and reactivity of para-substituted benzoylmethyltellurium(II and IV) compounds: observation of intermolecular C-H-O hydrogen bonding in the crystal structure of (p-MeOC6H4COCH2)2TeBr2

Bis(p-substituted benzoylmethyl)tellurium dibromides, (p-YC₆H₄COCH₂)₂TeBr₂, (Y=H (1a), Me (1b), MeO (1c)) can be prepared either by direct insertion of elemental Te across C_Rf-Br bonds (where C_Rf refers to α-carbon of a functionalized organic moiety) or by the oxidative addition of bromine to (p-YC₆H₄COCH₂)₂Te (Y=H (2a), Me (2b), MeO (2c)). Bis(p-substituted benzoylmethyl)tellurium dichlorides, (p-YC₆H₄COCH₂)₂TeCl₂ (Y=H (3a), Me (3b), MeO (3c)), are prepared by the reaction of the bis(p-substituted benzoylmethyl)tellurides 2a-c with SO₂Cl₂, whereas the corresponding diiodides (p-YC₆H₄COCH₂)₂TeI₂ (Y=H (4a), Me (4b), MeO (4c)) can be obtained by the metathetical reaction of 1a-c with KI, or alternatively, by the oxidative addition of iodine to 2a-c. The reaction of 2a-c with allyl bromide affords the diorganotellurium dibromides 1a-c, rather than the expected triorganotelluronium bromides. Compounds 1-4 were characterized by elemental analyses, IR spectroscopy, ¹H, ¹³C and ¹²⁵Te NMR spectroscopy (solution and solid-state) and in case of 1c also by X-ray crystallography. (p-MeOC₆H₄COCH₂)₂TeBr₂ (1c) provides, a rare example, among organotellurium compounds, of a supramolecular architecture, where C-H-O hydrogen bonds appear to be the non-covalent intermolecular associative force that dominates the crystal packing.     

Novel bicyclic hexanuclear copper(I) aggregate: Structure and solid state P CPMAS NMR spectra of [(Cu3L3)2] and [Cu(PPh3)2L] complexes of N-(diisopropoxythiophosphinyl)-N′-phenylthiourea (HL)

A new complex of N-thiophosphorylthiourea PhNHC(S)NHP(S)(OiPr)₂ (HL) of formula [(Cu₃L₃)₂] has been synthesized and characterized by single crystal X-ray diffraction, FT-IR, ¹H, ³¹P NMR in solution and by ³¹P CPMAS NMR spectroscopy in the solid state. A comparison of the structure and the spectral parameters of [(Cu₃L₃)₂] with those of the mononuclear analogue [Cu(PPh₃)₂L] was performed. In the solid state the aggregate [(Cu₃L₃)₂] represents the first example of a spontaneous “side-by-side” association of two neutral cyclic [Cu₃L₃] moieties using two Cu-S-Cu bridges formed by the sulfur atoms of the PS-groups. The values of the ¹J(³¹P-^63,65Cu) and ²J(³¹P-³¹P) coupling constants of the [Cu(PPh₃)₂]⁺ moiety in the solid state spectra are reported.