Syntheses, X-ray structural characterizations, and thermal stabilities of two nonclassical trinuclear vanadium(IV) complexes, (V3(μ3-O)O2)(μ2-O2P(CH2C6H5)2)6(H2O) and (V3(μ3-O)O2)(μ2-O2P(CH2C6H5)2)6(py), and polymeric complexes of stoichiometry (VO(O2PR2)2)∞, R2 = Ph2 and o-(CH2)2(C6H4)

The preparation and structural characterization of two trinuclear vanadium complexes, (V(3)(μ(3)-O)O(2))(μ(2)-O(2)P(CH(2)C(6)H(5))(2))(6)(H(2)O), 1, and (V(3)(μ(3)-O)O(2))(μ(2)-O(2)P(CH(2)C(6)H(5))(2))(6)(py), 2, are reported. In these nonclassical structures, the planar central core consists of the three vanadium atoms arranged in the form of an acute quasi-isosceles triangle with the central oxygen atom multiply bonded to the vanadium atom at the center of the vertex angle and weakly interacting with the two other vanadium atoms on the base sites, each of which contain one external multiply bonded oxygen atom. Reacting VO(acac)(2)in the presence of diphenylphosphinic acid affords (VO(O(2)PPh(2))(2))(∞), 3, while 2-hydroxyisophosphindoline-2-oxide at room temperature in CH(2)Cl(2) affords ((H(2)O)VO(O(2)Po-(CH(2))(2)C(6)H(4))(2))(∞), 4, and at 120 °C in EtOH yields (VO(O(2)P(o-(CH(2))(2)(C(6)H(4)))(∞), 5 on the basis of elemental analyses. The thermal and chemical stability of the complexes were assessed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurements. The bond strengths of the vanadium atoms to the OH(2) ligand in 1 and to the NC(5)H(5) ligand in 2 were assessed at 10.7 and 42.0 kJ/mol respectively. Room temperature magnetic susceptibility measurements reveal magnetic moments for trinuclear 1 and 2 at 3.02(1) and 3.05(1) μ(B/mol), and also close to spin only values (1.73 μ(B)) values for 3, 4, and 5 at 1.77(2), 1.758(7), and 1.77(3) μ(B), respectively. Variable-temperature, solid-state magnetic susceptibility measurements were conducted on complex 2 in the temperature range of 2.0-298 K and at an applied field of 0.5 T. Magnetization measurements at 2 and 4 K confirmed a very weak magnetic interaction between the vanadyl centers.     

Syntheses, 95Mo NMR Spectroscopy and Structures of Distorted Cubic Mo4(��3-O)4(��2-O2P(CH2C6H5)2)4O4 and the Open Mixed-Valent Cluster, Mo4(��3-O)2(��2-O2P(CH2C6H5)2)6O6

The reaction of MoO₂(acac)₂ and dibenzylphosphinic acid in ethanol leads to a red distorted cubic tetrameric cluster, Mo₄(??³-O)₄(??²-O₂P(CH₂C₆H₅)₂)₄O₄, and a pink open mixed-valent cluster, Mo₄(??³-O)₂(??²-O₂P(CH₂C₆H₅)₂)₆O₆, when the reduction is carried out at 120 and 75 °C, respectively. ⁹⁵Mo NMR spectroscopy revealed a singlet for Mo₄(??³-O)₄(??²-O₂P(CH₂C₆H₅)₂)₄O₄ (1) at 584.9 ppm (????_1/2 = 4500 Hz) and two resonances for Mo₄(??³-O)₂(??²-O₂P(CH₂C₆H₅)₂)₆O₆ (2) at 238.8 ppm (????_1/2 = 1250 Hz) and 6.4 ppm (????_1/2 = 5999 Hz), which were assigned to the Mo(V) and Mo(VI) sites, respectively. DFT geometries and ⁹⁵Mo DFT-GIAO chemical shifts for Mo₄(??³-O)₄(??²-O₂P(CH₃)₂)₄O₄ (3) and Mo₄(??³-O)₂(??²-O₂P(CH₃)₂)₆O₆ (4) are consistent with X-ray crystallography and ⁹⁵Mo NMR of 1 and 2. The open complex, Mo₄(??³-O)₂(??²-O₂P(CH₂C₆H₅)₂)₆O₆·2(CH₂Cl₂), exhibits a central Mo(V)?CMo(V) single bond at 2.6217(5) Å with each Mo(V) atom bonded to one oxo (trans-disposed) terminal ligand.     

Syntheses and Crystal Structures of Two Trinuclear Iron(Ⅲ) Carboxylate Complexes: [Fe3(μ3-O)(μ-O2CEt)6(H2O)3]Cl.3H2O and [Fe3(μ3-O)(μ-O2CEt)6Py3]Cl(Py=pyridine)

Two new oxo-centered trinuclear iron complexes [Fe3(μ3-O)(μ-O2CEt)6(H2O)3]Cl.3H2O 1 and [Fe3(μ3-O)(μ-O2CEt)6Py3]Cl 2 were prepared in non-aqueous solvent and their crystal structures have been determined. Crystal 1 is monoclinic, space group P21/n, a=9.909(3), b=24.467(8), c=14.542(7)(), β=107.85(4)° V=3356(4)()3, Z=4, Mr=765.52, Dc=1.52 g/cm3, μ=14.28 cm-1, F(000)=1588 and R=0.059, Rw=0.071 for 3745 unique reflections with I>3σ(I). Crystal 2 belongs to the monoclinic system with space group C2/c, a=13.750(3), b=18.439(4), c=16.696(3)(), β=93.42(3)°, V=4226(3)()3, Z=4, Mr=894.73, Dc=1.41 g/cm3, μ=11.4 cm-1, F(000)=2322 and R=0.058, Rw=0.062 for 2272 unique reflections with I>3σ(I). The two structures contain the same trimetal framework in which three iron(Ⅲ) atoms form a nearly equilateral triangle with a μ3-oxygen atom in the centre.     

[C5H4C(CH3)(C3H7)CH2CH=CH2]NdMg2(μ3-OH)(μ3-Cl)(μ2-Cl)3(THF)4Cl的合成和晶体结构分析

用Ｘ－射线衍射法测定了［Ｃ５Ｈ４Ｃ（ＣＨ３）（Ｃ３Ｈ７）ＣＨ２ＣＨ＝ ＣＨ２］ＮｄＭｇ２（μ３－ＯＨ）（μ３－Ｃｌ）（μ２－Ｃｌ）３（ＴＨＦ）４Ｃｌ的晶体结构。它属三斜晶系,空间群为Ｐ１－ ,ａ＝ １２．６９８（３）, ｂ＝ １３．６１６（３）, ｃ＝ １３．７１２（３）, α＝ ６８．９１（３）, β＝ ８４．３４（３）, γ＝ ６３．０７（３）°, Ｖ＝ １９６６（１）３, Ｍｒ＝ ８４９．７４, Ｄｘ＝ １．４１２ ｇ·ｃｍ － ３, μ＝ １．７２９７ ｍ ｍ － １, Ｆ（０００）＝ ８４０, Ｚ＝ ２, Ｒ＝ ０．０７３, ｗ Ｒ＝ ０．０８６（Ｉ≥３σ（Ｉ））。分子中Ｎｄ（Ⅲ）原子的配位数为八,形成一个严重扭曲的八面体结构。两个Ｍｇ 原子的配位情况相似,它们的配位数都是六,构成两个扭曲的八面体。这三个八面体通过三个共用平面联接     

Preparation of organozirconium aromatic compounds in mixed aqueous-organic solvents: X-ray structures of [Cp2ZrCl(μ2-O′,O′′C-C6H5)], [(CpZr)3(μ2-O′,O′′C-C6H3Cl2)3(μ3-OH)(μ2-OH)3](Cl2C6H3COO)2, and [(CpZr)3(μ2-O′,O′′C-C6H4Cl)3(μ3-OH)(μ2-OH)3]Cl2·CH2Cl2

A new and facile method is presented for the synthesis of zirconocene carboxylate compounds, in which zirconocene dichloride (Cp₂ZrCl₂) is dissolved in 1 M aqueous HCl solution and the requisite ligand is dissolved in an organic solvent. Five such compounds [Cp₂ZrCl(μ₂-O′,O′′C-C₆H₅)] (1), [Cp₂ZrCl(μ₂-O′,O′′C-C₆H₃Cl₂)] (2), [Cp₂Zr(μ₂-O′,O′′C-C₆H₃(OH)Cl)₂] (3), [Cp₂Zr(μ₂-O′,O′′C-C₆H₃(OH)(NO₂))₂] (4), and [Cp₂Zr(μ₂-O′,O′′C-C₆H(OH)Cl₃)₂] (5) have been obtained by this method. The effect of pH on the stability of Cp₂ZrCl₂ in 1 M HCl solution has been investigated by UV/vis spectrophotometry and ¹H NMR spectrometry. The results showed that the aqueous Cp₂ZrCl₂ solutions became less stable with increasing pH, liberating cyclopentadiene. Accordingly, at higher pH (～7), two trinuclear zirconium monocyclopentadienyl compounds, [(CpZr)₃(μ₂-O′,O′′C-C₆H₃Cl₂)₃(μ₃-OH)(μ₂-OH)₃](Cl₂C₆H₃COO)₂ (6) and [(CpZr)₃(μ₂-O′,O′′C-C₆H₄Cl)₃(μ₃-OH)(μ₂-OH)₃]Cl₂·CH₂Cl₂ (7), were obtained. All compounds 1–7 have been characterized by FT-IR, ¹H NMR spectra and elemental analysis. In all of the compounds, the aromatic acid acts as a bidentate ligand in coordinating to the zirconium; both chelating and bridging modes are observed. X-ray crystallographic studies on 1, 6, and 7 have revealed that the geometries at zirconium are distorted octahedral in 6 and 7, and distorted trigonal-bipyramidal in 1.     

Complexing and ion selective properties of some acid type phosphoryl podands. The crystal and molecular structures of 1,5-bis(2-dihydroxyphosphoryl-4-ethylphenoxy)-3-oxapentane dihydrate [(HO)2(O)P(C6H3CH2CH3)(OCH2CH2)2O (C6H3CH2CH3)P(O)(OH)2] · 2H2O

The synthesis of 1,5-bis(2-dihydroxyphosphoryl-4-ethylphenoxy)-3-oxapentane [(HO)₂(O)P(C₆H₃CH₂CH₃)(OCH₂CH₂)₂O(C₆H₃CH₂CH₃)P(O)(OH)₂] (H₄K²) and single crystal X-ray diffraction study of H₄K² · 2H₂O (I) are described. The crystals are orthorhombic, a = 33.291(4) Å, b = 8.9374(10) Å, c = 8.1021(9) Å, V = 2410.6(5) ų, Z = 4, space group Cmc2₁, R = 0.0484 for 2566 reflections with I > 2σ(I). In I, the molecules of H₄K² are hydrogen-bonded to two crystallographically independent H₂O molecules to give neutral conglomerates H₄K² · 2H₂O. The electroanalytical characteristics of poly(vinyl chloride) membranes based on H₄K² were tested. Cu²⁺ and Zn²⁺ complexes with H₄K² and Er³⁺, Nd³⁺, and complexes with H₄K², 1,5-bis[2-(dihydroxyphosphoryl-4-methoxy)phenoxy]-3-oxapentane, 1,5-bis[2-(dihydroxyphosphinyl)phenoxy]-3-oxapentane, and 1,8-bis[2-(dihydroxyphosphinyl)phenoxy]-3,6-dioxaoctane were prepared.     

Synthesis and structure of the organoantimony peroxide solvates [Sb4(μ2-O)4(O2)2(C6H3MeO-2,Br-5)8]·1.5C4H8O2 and [Sb4(μ2-O)4(O2)2(C6H3MeO-2,Br-5)8]·6C4H8O2

The organoantimony peroxide (Ar₂SbO)₄(O₂)₂ (Ar = C₆H₃OMe-2, Br-5) was synthesized by the oxidation of Ar3Sb with hydrogen peroxide in the presence or acetoxime or acetophenone oxime in dioxane. The product crystallizes with various content of the solvent molecules in the crystal unit cell [1.5 (I) and 6 (II), respectively]. An X-ray diffraction analysis of the solvates was performed. Four antimony atoms in the peroxide are in the octahedral coordination, and are linked through bridging oxygen atoms and two peroxide groups. The distances Sb-C, Sb-O_bridge, Sb-O_peroxide, O-O and Sb...Sb are 2.117–2.122, 1.960–1.972, 2.193–2.235, 1.461, 1.465 and 3.223–3.237 Å in I, and 2.112, 2.119, 1.957, 1,966, 2.204, 2,246, 1,467, and 3.2439 Å in II.     

Syntheses and Crystal Structures of (H3O)(C3H5N2)[Mn(OH)6 Mo6O18]·3.5H2O and (H3O)3[Co(OH)6Mo6O18]·7H2O

The crystals of the title compounds (H3O)(C3H5N2)[Mn(OH)6Mo6O18]·3.5H2O 1 and (H3O)3[Co(OH)6Mo6O18]·7H2O 2 have been prepared and structurally determined by X-ray single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group C2/c with a = 21.5018(9), b = 10.9331(5), c = 11.8667(5)A,β = 95.3570(10)o, V = 2777.5(2)A3, Z = 4, Dc = 2.802 g/cm3, Mr = 1171.80,μ(MoKα) = 3.173 mm-1, F(000) = 223, the final R = 0.0458 and wR = 0.1041 for 2093 observed reflections (I>2σ(I)); Compound 2 crystallizes in monoclinic, space group P21/c with a = 11.4042(12), b = 10.9481(11), c = 11.6722(12)A, β= 99.948(2)o, V = 1435.4(3)A3, Z = 2, Dc = 2.794 g/cm3, Mr = 1207.80,μ(MoKα) = 3.223 mm-1, F(000) = 1160, the final R = 0.0544 and wR = 0.1066 for 1906 observed reflections (I > 2σ(I)). Both compounds 1 and 2 adopt the Anderson structure, in which the anion is of centrosymmetry and formed by six octahedral edge-sharing MoO6 units surrounding the central MO6 (M = Mn or Co) octahedron.     

[(C6H5 NO2)Pr(H2O)4](CrMo6O24H6)·(C6H5NO2)·2.5H2O的合成与晶体结构

用常规合成方法制备了基于Anderson结构阴离子的二维层状化合物[(C6H5NO2)2Pr(H2O)4](CrMo6O24H6)·2.5H2O,通过红外光谱和X射线单晶衍射对其进行了表征.结果表明,该化合物属于单斜晶系,C2/c空间群.a=2.3442(9)nm,b=1.3291(5)nm,c=2.458(1)nm,β=103.08(1)°,V=7.460(5)nm3,R1=0.0727,wR2=0.1903.结构分析表明,[CrMo6O24H6]3-阴离子通过端氧担载一个配位的Pr3+离子形成中性的(C6H5NO2)Pr(H2O)4(CrMo6O24H6)基团,相邻的中性基团在Ot—Pr—Ot桥联下形成一维链,链与链又通过异烟酸的桥联形成二维层状结构.     

Reactions of Triruthenium Clusters with Quinolines: X-Ray Structures of [Ru3(μ-CO)(CO)7{μ3-η2-P(C6H5)CH2P(C6H5)2)}{μ-η2-C9H5(CH3)N}] and [Ru3(CO)10(μ-H){μ-η2-C9H6N}]

The reactions of [Ru₃(CO)₁₀(μ-dppm)] 4 with quinolines afforded [Ru₃ (μ-CO)(CO)₇{μ₃-η²-P(C₆H₅)CH₂P(C₆H₅)₂)}{μ-η²-C₉H₅(R)N}] (8, R = 4-Me; 9, R = H) as the major products along with small amounts of known compound [Ru₃(CO)₉{μ₃-η³-P(C₆H₅)CH₂P(C₆H₅)(C₆H₄)}] 5. The molecular structure of 8 has been determined by single crystal X-ray studies. The reaction of 5 with 4-methylquinoline in refluxing cyclohexane afforded 8 and two known dinuclear compounds, [Ru₂(CO)₆{μ-CH₂P(C₆H₅)(C₆H₄)P(C₆H₅}] 10 and [Ru₂(CO)₆ {μ-(C₆H₄)P(C₆H₅)(CH₂)P(C₆H₅}] 11, in 40, 12, and 10% yields, respectively. The compounds 10 and 11 are also formed from the thermolysis of 4 in addition to the major compound 5. The solid state structure of the previously reported [Ru₃(CO)₁₀(η-H){μ-η²-C₉H₆N}] 2a is also reported for comparison.     

Protonation and acylation of the heterometallic complexes (μ-H)Os3(μ-O2CC5H4FeCp)(CO)10 and Fe{(μ-O2CC5H4)(μ-H)Os3(CO)10}2

The reactions of the heterometallic complexes (-H)Os₃(-O₂CC₅H₄FeCp)(CO)₁₀ (1) and Fe{(-O₂CC₅H₄)(-H)Os₃(CO)₁₀}₂ (2) with CF₃COOH, CF₃SO₃H, and AcCl were studied. The reaction of 1 with CF₃COOH involves interaction with the Cp ligands, protonation of the O atom of the bridging carboxylate group, and oxidative degradation of the complex. At low concentrations, CF₃SO₃H protonates the O atom of the bridging carboxylate group, while at high concentrations, degradation of the complex takes place. The reaction of complex 2with either CF₃COOH or low concentrations of CF₃SO₃H results in successive elimination of two [(-H)Os₃(CO)₁₀] cluster fragments due to protonation of the O atoms of the carboxylate groups. In the case of high CF₃SO₃H concentrations, the Os—Os bonds of both cluster fragments of 2 are also protonated to give the [Fe{(-O₂CC₅H₄)(-H)₂Os₃(CO)₁₀}₂]²⁺ dication. The Friedel—Crafts acylation of 1 takes place only when a large excess of AcCl and AlCl₃ is used to give two new complexes, (-H)Os₃(-O₂CC₅H₄FeC₅H₄C(O)CH₃)(CO)₁₀ and (-H)Os₃(-O₂CC₅H₃C(O)CH₃FeCp)(CO)₁₀ in a 2 : 1 ratio.     

Os3(CO)9(μ3-AsC6H4CH3)(μ3-C6H3CH3) synthesis and crystal structure

One of the products of the reaction of the activated cluster Os₃(CO)₁₁(NCMe) with As(p-tol)₃ in refluxing nonane has been shown by spectroscopic and X-ray crystallographic methods to be Os₃(CO)₉(μ₃-AsC₆H₄CH₃)(μ₃-C₆H₃CH₃), which contains a benzyne moiety bonded asymmetrically from one carbon to one osmium via a σ bond and from a second carbon to form a bridge between the remaining two osmium atoms.     

Thermochemistry and kinetics of the 2-butanone-4-yl CH3C(=O)CH2CH2• + O2 reaction system

Thermochemistry and kinetic pathways on the 2-butanone-4-yl (CH₃C(=O)CH₂CH₂•) + O₂ reaction system are determined. Standard enthalpies, entropies, and heat capacities are evaluated using the G3MP2B3, G3, G3MP3, CBS-QB3 ab initio methods, and the B3LYP/6-311g(d,p) density functional calculation method. The CH₃C(=O)CH₂CH₂• radical + O₂ association reaction forms a chemically activated peroxy radical with 35 kcal mol⁻¹ excess of energy. The chemically activated adduct can undergo RO−O bond dissociation, rearrangement via intramolecular hydrogen transfer reactions to form hydroperoxide-alkyl radicals, or eliminate HO₂ and OH. The hydroperoxide-alkyl radical intermediates can undergo further reactions forming ketones, cyclic ethers, OH radicals, ketene, formaldehyde, or oxiranes. A relatively new path showing a low barrier and resulting in reactive product sets involves peroxy radical attack on a carbonyl carbon atom in a cyclic transition state structure. It is shown to be important in ketones when the cyclic transition state has five or more central atoms.     

Study of allylic rearrangement in (μ-H)Os3(μ-O=CNRCH2CH=CH2)(CO)10 (R=H or CH3) clusters

The migration of the double bond in the allylcarboxamide ligands of (μ-H)Os₃(μ-O=CN RCH₂CH=CH₂) (CO)₁₀ (R=H (1) or CH₃ (2)), (μ-D)Os₃(μ-O=CNDCH₂CH=CH₂) (CO)₁₀, and (μ-H)Os₃(μ-O=CNHCD₂CH=CH₂)(CO)₁₀ clusters was studied by¹H,²H, and¹³C NMR spectroscopy. Neither μ-D nor ND groups in the deuterated complexes are directly involved in prototropic processes of allylic rearrangement. Initially, the deuterium atom of the CD₂ group migrates to the ψ-carbon atom of the allyl fragment to form the −CD=CH-CH₂D propenyl moiety, in which the deuterium and hydrogen atoms are gradually redistributed between the ψ-and β-carbon atoms. The triosmium cluster complexes containing the bridging carboxamide ligands O=CNRR' catalyze the allylic rearrangement ofN-allylacetamide. Based on the data obtained, the probable scheme of the allylic rearrangements in clusters1 and2 was proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2182–2186, November, 1999.     

Synthesis,structure, and properties of a new trinuclear iron cluster, [(MeOH)(H2O)2Fe3(μ3-O)(μ-OOCC6H4OCH2C5H4NH)6] (ClO4)7 · · 8MeOH · 3.5H2O

Reactions of iron(m) salts with a new bidentate ligand, which is potentially capable of forming binuclear iron complexes upon complexation, were studied. Under various conditions, we succeeded in isolating only the trinuclear cationic complex (Fe^III ₃(O₂CR)6(₃-)17+ (1), where RCO₂ is 2-(pyrid-2-ylmethoxy)benzoic acid protonated at the pyridyl moiety. The structure of 1 was established by spectral, magnetic, and X-ray structural studies. Cyclic voltammetry in McCN in the temperature range from -35 to 20 °C demonstrated that 1 undergoes successive Fe^IIIFe^II reduction in three one-electron stages, which is indicative of the electronic interaction between iron atoms in the complex.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 2086–2092, August, 1996.     

Expansion of antimonato polyoxovanadates with transition metal complexes: (Co(N3C5H15)2)2[{Co(N3C5H15)2}V15Sb6O42(H2O)]·5H2O and (Ni(N3C5H15)2)2[{Ni(N3C5H15)2}V15Sb6O42(H2O)]·8H2O

Two new polyoxovanadates (Co(N(3)C(5)H(15))(2))(2)[{Co(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)]·5H(2)O (1) and (Ni(N(3)C(5)H(15))(2))(2)[{Ni(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)]·8H(2)O (2) (N(3)C(5)H(15) = N-(2-aminoethyl)-1,3-propanediamine) were synthesized under solvothermal conditions and structurally characterized. In both structures the [V(15)Sb(6)O(42)(H(2)O)](6-) shell displays the main structural motif, which is strongly related to the {V(18)O(42)} archetype cluster. Both compounds crystallize in the triclinic space group P1 with a = 14.3438(4), b = 16.6471(6), c = 18.9186(6) ?, α = 87.291(3)°, β = 83.340(3)°, γ = 78.890(3)°, and V = 4401.4(2) ?(3) (1) and a = 14.5697(13), b = 15.8523(16), c = 20.2411(18) ?, α = 86.702(11)°, β = 84.957(11)°, γ = 76.941(11)°, and V = 4533.0(7) ?(3) (2). In the structure of 1 the [V(15)Sb(6)O(42)(H(2)O)](6-) cluster anion is bound to a [Co(N(3)C(5)H(15))(2)](2+) complex via a terminal oxygen atom. In the Co(2+)-centered complex, one of the amine ligands coordinates in tridentate mode and the second one in bidentate mode to form a strongly distorted CoN(5)O octahedron. Similarly, in compound 2 an analogous NiN(5)O complex is joined to the [V(15)Sb(6)O(42)(H(2)O)](6-) anion via the same attachment mode. A remarkable difference between the two compounds is the orientation of the noncoordinated propylamine group leading to intermolecular Sb···O contacts in 1 and to Sb···N interactions in 2. In the solid-state lattices of 1 and 2, two additional [M(N(3)C(5)H(15))(2)](2+) complexes act as countercations and are located between the [{M(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)](4-) anions. Between the anions and cations strong N-H···O hydrogen bonds are observed. In both compounds the clusters are stacked along the b axis in an ABAB fashion with cations and water molecules occupying the space between the clusters. Magnetic characterization demonstrates that the Ni(2+) and Co(2+) cations do not significantly couple with the S = 1/2 vanadyl groups. The susceptibility data can be successfully reproduced assuming a distorted ligand field for the Co(2+) ions (1) and an O(h)-symmetric Ni(2+) ligand field (2).     

Structure of (C3H5NH3)2H2P2O7·H2O

The bis(cyclopropylammonium)dihydrogenodiphosphate monohydrate is a new diphosphate associated with the organic molecule C₃H₅NH₂. We report the chemical preparation and the crystal structure of this organic cation diphosphate. (C₃H₅NH₃)₂H₂P₂O₇.H₂O is orthorhombic (S.G. : P2₁2₁2₁), with Z = 4 and the following unit-cell parameters : a = 4.828(1) Å, b = 11.011(1) Å, c = 25.645(2) Å. The P₂O₇ groups and H₂O water molecules form a succession of bidimensional layers perpendicular to the c axis. The organic cations ensure the three-dimensional cohesion by NH-O hydrogen bonds.