Beiträge zur Kristallchemie und zum thermischen Verhalten von wasserfreien Phosphaten. XXXIII [1] In2P2O7, ein Indium(I)‐diphosphato‐indat(III) und In4(P2O7)3 — Darstellung,Kristallisation und Kristallstrukturen

Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXXIII [1] In₂P₂O₇ an Indium(I)‐diphosphatoindate(III), and In₄(P₂O₇)₃ — Synthesis, Crystallization, and Crystal Structure Solid state reactions via the gas phase lead to the new mixed‐valence indium(I, III)‐diphosphate In₂P₂O₇. Colourless single crystals of In₂P₂O₇ have been grown by isothermal heating of stoichiometric amounts of InPO₄ and InP (800 °C; 7d) using iodine as mineralizer. The structure of In₂P₂O₇ [P2₁/c, a = 7.550(1) Å, b = 10.412(1) Å, c = 8.461(2) Å, b = 105.82(1)°, 2813 independent reflections, 101 parameter, R1 = 0.031, wR2 = 0.078] is the first example for an In⁺ cation in pure oxygen coordination. Observed distances d(In^I‐O) are exceptionally long (d_min(In^I‐O) = 2.82 Å) and support assumption of mainly s‐character for the lone‐pair at the In⁺ ion. Single crystals of In₄(P₂O₇)₃ were grown by chemical vapour transport experiments in a temperature gradient (1000 → 900 °C) using P/I mixtures as transport agent. In contrast to the isostructural diphosphates M₄(P₂O₇)₃ (M = V, Cr, Fe) monoclinic instead of orthorhombic symmetry has been found for In₄(P₂O₇)₃ [P2₁/a, a = 13.248(3) Å, b = 9.758(1) Å, c = 13.442(2) Å, b = 108.94(1)°, 7221 independent reflexes, 281 parameter, R1 = 0.027, wR2 = 0.067].     

Beiträge zum thermischen Verhalten und zur Kristallchemie von wasserfreien Phosphaten XXXII [1] Neue Orthophosphate des zweiwertigen Chroms — Mg3Cr3(PO4)4, Mg3, 75Cr2, 25(PO4)4, Ca3Cr3(PO4)4 und Ca2, 00Cr4, 00(PO4)4

Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXXII. New Orthophosphates of Divalent Chromium — Mg₃Cr₃(PO₄)₄, Mg_{3, 75}Cr_{2, 25}(PO₄)₄, Ca₃Cr₃(PO₄)₄ and Ca_{2, 00}Cr_{4, 00}(PO₄)₄ Solid state reactions via the gas phase led in the systems A₃(PO₄)₂ / Cr₃(PO₄)₂ (A = Mg, Ca) to the four new compounds Mg₃Cr₃(PO₄)₄ ( A ), Mg_3.75Cr_2.25(PO₄)₄ ( B ), Ca₃Cr₃(PO₄)₄ ( C ), and Ca_2.00Cr_4.00(PO₄)₄ ( D ). These were characterized by single crystal structure investigations [( A ): P2₁/n, Z = 1, a = 4.863(2) Å, b = 9.507(4) Å, c = 6.439(2) Å, β = 91.13(6)°, 1855 independend reflections, 63 parameters, R1 = 0.035, wR2 = 0.083; ( B ): P2₁/a, Z = 2, a = 6.427(2) Å, b = 9.363(2) Å, c = 10.051(3) Å, β = 106.16(3)°, 1687 indep. refl., 121 param., R1 = 0.032, wR2 = 0.085; ( C ): P‐1, Z = 2, a = 8.961(1) Å, b = 8.994(1) Å, c = 9.881(1) Å, α = 104.96(2)°, β = 106.03(2)°, γ = 110.19(2)°, 2908 indep. refl., 235 param., R1 = 0.036, wR2 = 0.111; ( D ): C2/c, Z = 4, a = 17.511(2) Å, b = 4.9933(6) Å, c = 16.825(2) Å, β = 117.95(1)°, 1506 indep. refl., 121 param., R1 = 0.034, wR2 = 0.098]. The crystal structures contain divalent chromium on various crystallographic sites, each showing a (4+n)‐coordination (n = 1, 2, 3). For the magnesium compounds and Ca_2.00Cr_4.00(PO₄)₄ a disorder of the divalent cations Mg²⁺/Cr²⁺ or Ca²⁺/Cr²⁺ is observed. Mg_3.75Cr_2.25(PO₄)₄ adopts a new structure type, while Mg₃Cr₃(PO₄)₄ is isotypic to Mg₃(PO₄)₂. Ca₃Cr₃(PO₄)₄ and Ca_2.00Cr_4.00(PO₄) ₄ are structurally very closely related and belong to the Ca₃Cu₃(PO₄)₄‐structure family. The orthophosphate Ca₉Cr(PO₄)₇, containing trivalent chromium, has been obtained besides C and D .     

Monosubstituted Trinuclear and Tetranuclear VIB Metal Carbonyl Complexes: Syntheses of [{M(CO)5}3(Pf-Pf-Pf)] [Pf-Pf-Pf = PhP(CH2CH2PPh2)2] and [{M(CO)5}4(P-Pf3)] [P-Pf3 = P(CH2CH2PPh2)3] (M = Cr,Mo) and Crystal Structures of the Latter Three

The triligate trimetallic complexes, [{M(CO)₅}₃(Pf-Pf-Pf)] and tetraligate tetrametallic complexes, [{M(CO)₅}₄(P-Pf₃)] (M = Cr and Mo), were prepared from [M(CO) ₆] and the corresponding ligands in MeCN/CH₂Cl₂ promoted by Me₃NO at 0 °C. Crystals of trimer lb are monoclinic, space group P 2₁/n, with a = 13.407(3), b = 15.002(5), c = 26.52(1) Å, β = 90.65(2)°, Z = 4, and R = 0.060 for 2760 observed reflections. Crystals of tetramer 2a are monoclinic, space group P 2₁/c, with a – 14.183(8), b = 29.880(4), c = 16.103(2) Å, β = 94.98(3)°, Z = 4, and R = 0.039 for 5014 observed reflections. Crystals of 2b are monoclinic, space group C 2/c, with a = 42.120(8), b = 13.679(1), c = 23.486(2) Å, β = 92.14(1)°, Z = 8, and R = 0.032 for 6897 observed reflections. Each phosphorus atom of the ligands is coordinated to the M(CO)₅ moiety in each title compounds. The geometry of the four metals is a distorted tetrahedron for the tetramers.     

Complexation of Alkali Triflates by Crown Ethers: Synthesis and Crystal Structure of [Na(12‐crown‐4)2][SO3CF3], [Na(15‐crown‐5)][SO3CF3], [Rb(18‐crown‐6)][SO3CF3], and [Cs(18‐crown‐6)][SO3CF3]

Complexes of trifluoromethanesulfonates (triflates) with alkali metals Na, Rb, Cs have been prepared in the presence of various macrocyclic polyether crowns [(12‐crown‐4), (15‐crown‐5) and (18‐crown‐6)]. Depending on the combination of alkali ion with crown, the complexes include separated ion pairs [Na(12‐crown‐4)₂] [SO₃CF₃] ( 1 ) and contact ion pairs [Na(15‐crown‐5)] [SO₃CF₃] ( 2 ), [Rb(18‐crown‐6)] [SO₃CF₃] ( 3 ), and [Cs(18‐crown‐6)] [SO₃CF₃] ( 4 ), in which the triflate acts as a bidentate ligand. It is shown that the choice of crown ether is of paramount importance in determining the solid‐state structural outcome. The complex resulting from the pairing of crown ether ( 1 ) develops, when the crown ether is too small in relation to the alkali ion radius. When the cavity size of the crown ether is matched with the alkali ion radius, simple monomeric structures are identified in 2 , 3 and 4 . The title compounds crystallize in the monoclinic crystal system: 1 : space group P2/c with a = 9.942(3), b = 11.014(2), c = 10.801(3) Å, β = 97.30(2)°, V = 1173.1(4) ų, Z = 2, R1 = 0.0812, wR2 = 0.1133: 2 : space group P2₁/m with a = 7.949(2), b = 12.063(3), c = 9.094(2) Å, β = 105.98(2)°, V = 838.3(4) ų, Z = 2, R1 = 0.0869, wR2 = 0.1035: 3 : space group P2₁/c with a = 12.847(5), b = 8.448(2), c = 22.272(6) Å, β = 122.90(3)°, V = 2029.5(1) ų, Z = 4, R1 = 0.0684, wR2 = 0.1044: 4 : space group P2₁/n with a = 12.871(3), b = 8.359(1), c = 19.019(4) Å, β = 92.61(2)°, V = 2044.2(6) ų, Z = 4, R1 = 0.0621, wR2 = 0.0979.     

Preparation and Structure Determination of SrMn2(PO4)2 and Redetermination of b ′‐Mn3(PO4)2

Pale rose single crystals of SrMn₂(PO₄)₂ were obtained from a mixture of SrCl₂ · 6 H₂O, Mn(CH₃COO)₂, and (NH₄)₂HPO₄ after thermal decomposition and finally melting at 1100 °C. The new crystal structure of strontium manganese orthophosphate [P‐1, Z = 4, a = 8.860(6) Å, b = 9.054(6) Å, c = 10.260(7) Å, α = 124.27(5)°, β = 90.23(5)°, γ = 90.26(6)°, 4220 independent reflections, R1 = 0.034, wR2 = 0.046] might be described as hexagonal close‐packing of phosphate groups. The octahedral, tetrahedral and trigonal‐bipyramidal voids within this [PO₄] packing provide different positions for 8‐ and 10‐fold [SrO_x] and distorted octahedral [MnO₆] coordination according to a formulation Mn Mn Mn Sr (PO₄)₄. Single crystals of β′‐Mn₃(PO₄)₂ (pale rose) were grown by chemical vapour transport (850 °C → 800 °C, P/I mixtures as transport agent). The unit cell of β′‐Mn₃(PO₄)₂ [P2₁/c, Z = 12, a = 8.948(2) Å, b = 10.050(2) Å, c = 24.084(2) Å, β = 120.50°, 2953 independent reflections, R1 = 0.0314, wR2 = 0.095] contains 9 independent Mn²⁺. The reinvestigation of the crystal structure led to distinctly better agreement factors and significantly reduced standard deviations for the interatomic distances.     

Ru(II) COMPLEXES CONTAINING CHELATING PHOSPHINE LIGANDS. SYNTHESIS,CHARACTERIZATION, AND X-RAY CRYSTAL STRUCTURES OF DICHLOROBIS(1,2-BIS(DIPHENYLPHOSPHINO)ETHANE)Ru(II) AND THE COORDINATIVELY UNSATURATED TRIGONAL-BIPYRAMIDAL CATION,CHLOROBIS-(1,2-BIS(DIPHENYLPHOSPHINO)ETHANE)Ru(II)

Abstract

The reaction of trans-RuCl₂(dppe)₂ (1), with AgBF₄ in tetrahydrofuran leads to abstraction of one of the halide ligands to produce the trigonal-bipyrimidal complex, [RuCl(dppe)₂]BF₄ (2). Both products are characterized by ³¹P NMR spectroscopy and their crystal structures determined. For the coordinatively unsaturated trigonal-bipyramidal complex (2), we found no evidence for the presence of more than one species or fluxional behaviour at room temperature in the ³¹P NMR spectrum. This complex was found to possess a trigonal-bipyramidal geometry in the solid state. Crystals of 1 are monoclinic, space group P2₁/c with a = 23.713(4)Å, b=11.156(1)Å, c = 17.595(2)Å, β=103.23(1) and v=4531(1)ų. Convergence to conventional R values of R=0.043 and R_w = 0.042 was obtained for 416 variable parameters and 2746 reflections with I>3σ(I). Compound 2 in triclinic, P1, a=12.482(3)Å, b=12.543(3)Å, c=17.582(3)Å, α = 87.52(2)°, β= 72.70(2)° γ = 74.35(2)° and V= 2529(1)ų. Values of R = 0.072 and R_w = 0.097 were obtained for 487 variable parameters and 3242 reflections with I>3σ(I)     

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.     

Coordination Chemistry of Sulfonyl Amides. 2 The Crystal Structure of Copper(II) and Silver(I) Complexes of N,N-4-Toluenesulfonyl-2-Pyridylaminato Ligand

Three structures containing the N,N-4-toluenesulfonyl-2-pyridylaminato ligand are presented. The brown crystal of Cu₂L₄ (L =N,N-4-toluenesulfonyl-2-pyridylaminato) was found to crystallize in the monoclinic space group P2,/c with a = 15.762(12), b = 15.552(5), c = 20.505(11) Å, β = 104.14(7)°; V = 4874(5) Å^3;Z = 4; the final R_F = 0.050, R_WF = 0.049 for 5142 observed reflections and 612 variables. The Cu-Cu distance is small, 2.516(2) Å and the complex is diamagnetic at room temperature. The colorless crystal of Ag₂L was found to crystallize in the monoclinic space group P2_t/n with a = 9.620(2), b = 5.625(2), c ? 23.250(3) Å, Å = 94.72(1)°; V = 1254.0(5) ų; Z = 2; the final R_F = 0.027; R_WF = 0.028 for 1929 observed reflections and 164 variables. The Ag-Ag distance is 2.739(1) Å The green crystal of CuL₂ (py)₂was found to crystallize in the monoclinic space group P2₁ with a = 9.366(2), b = 20.615(7), c = 9.862(2) Å,β = 116.73(2)°; V = 1700.5(8) ų; Z = 2; the final R_F = 0.037; R_WF = 0.038 for 1636 observed reflections and 423 variables. A reversible transformation between Cu₂L₄ and CuL₂(py)₂ is reported.     

Refinement of the Superstructure of C-Type Gallium Tris(metaphosphate), Ga(PO3)3

Single crystals of Ga(PO₃)₃ were grown in polyphosphoric acid melts by heating a mixture of Ga₂O₃ and H₃PO₄ (350 °C, 7 d). The compound belongs to the series of metaphosphates M^III(PO₃)₃ forming the C-type structure (monclinic, Cc, Z = 12, a = 13.0058(21), b = 18.915(3), c = 9.3105(15) Å, β = 126.900(11), 5348 independent reflections (I > 0); 354 variables; 39 atoms in asymetric unit; R1 = 0.048, wR2 = 0.1034). The structure is characterized by a superstructure with tripled monoclinic b-axis. Three crystallographically independent Ga^IIIO₆ octahedra (d¯(Ga–O) = 1.950 Å) are linked by ¹_∞(PO₃)^– chains.     

Penta‐Ammoniates of Aluminium Halides: The Crystal Structures of AlX3·5NH3 with X = Cl,Br, I

Colourless crystals grow in the colder part of a glass ampoule when AlX₃·5NH₃ with X = Cl, Br, I is heated for 3—6 d to 330 °C (Cl), 350 °C (Br) and 400 °C (I), respectively. The chloride forms hexagonal prisms while the bromide and iodide were obtained as a bunch of lancet‐like crystals. The chloride and bromide crystallize isotypic whereas the iodide has an own structure type. All three are related to the motif of the K₂PtCl₆ type. So the formula of the ammoniates may be written as X₂[Al(NH₃)₅X] ≙ [Al(NH₃)₅X]X₂. The compounds are characterized by the following crystallographic data AlCl₃·5NH₃: Pnma, Z = 4, a = 13.405 (1)Å, b = 10.458 (1)Å, c = 6.740 (2)Å AlBr₃·5NH₃: Pnma, Z = 4, a = 13.808 (2)Å, b = 10.827 (1)Å, c = 6.938 (1)Å AlI₃·5NH₃: Cmcm, Z = 4, a = 9.106 (2)Å, b = 11.370 (2)Å, c = 11.470 (2)Å For the chloride and the bromide the structure determinations were successful including hydrogen positions. All three compounds contain octahedral molecular cations [Al(NH₃)₅X]²⁺ located in distorted cubes formed by the remaining 2X^— ions. The orientation of the octahedra to each other is clearly different for those with X = Cl, Br in comparison to the one with X = I.     

Molecular and Crystal Structures of Cp2YbX(THF) (X = Cl,Br)

Cp₂YbCl(THF) crystallizes in the orthorhombic space group Pnma (Z = 4, a = 13.109(5), b = 11.851(4), c = 9.377(3) Å, R1 = 0.0412, wR2 = 0.0482), while Cp₂YbBr(THF) is monoclinic (P2₁/n, Z = 4, a = 8.149(2), b = 12.997(2), c = 14.388(3) Å, β = 105.73(2)°, R1 = 0.0425, wR2 = 0.0436). The ligand arrangements around the formally eight coordinate Yb atoms are pseudo tetrahedral. These two determinations complete the first series of [Cp₂LnX(L)] (X = F, Cl, Br, I) structures covering all halogens for one lanthanoid and cyclopentadienyl group.     

Ein Beitrag über Oxometallate mit trigonal planaren BO3-Polyedern Ni2MBO5 (M = Ga,Fe, Al,Cr)

A Contribution about Oxometallates Containing Trigonal Planar BO₃-Polyhedra. Ni₂MBO₅ (M = Ga, Fe, Al, Cr) (I) Ni₂AlBO₅, (II) Ni₂FeBO₅, and (III) Ni₂GaBO₅ were investigated by single crystal X-ray technique. They crystallize with orthorhombic symmetry, space group D—Pbam; I: a = 9.102; b = 12.011; c = 2.944 Å; II: a = 9.200; b = 12.210; c = 3.006 Å; III: a = 9.200; b = 12.154; c = 2,986 Å; Z = 4. X-ray powder data indicate that Ni₂CrBO₅ is isotypic. It was possible to study the metal distribution in Ni₂AlBO₅. Ni²⁺ and Al³⁺ ions occupy the point positions partly disordered.     

Die Tieftemperaturmodifikationen von Ag6Si2O7 und Ag6Ge2O7 – Darstellung,Kristallstruktur und Vergleich der Ag?Ag-Abstände

On the Low Temperature Modifications of Ag₆Si₂O₇ and Ag₆Ge₂O₇ – Synthesis, Crystal Structure, and Comparison of Ag? Ag Distances For the first time, single crystals of Ag₆Si₂O₇ and Ag₆Ge₂O₇ have been obtained by solid state reactions of the binary oxides at temperatures of 350°C while applying oxygen pressures of 700 bar. According to the results of X-ray crystal structure determinations both compounds crystallize isostructural in P2₁ (Ag₆Si₂O₇: a = 5.3043(5) Å, b = 9.7533(7) Å, c = 15.9283(13) Å, β = 91.165(8)°, 3881 independent reflections, R1 = 3.3%, wR2 = 7.2%; Ag₆Ge₂O₇: a = 5.3713(4) Å, b = 9.9835(8) Å, c = 16.2249(14) Å, β = 90.904(8)°, 2111 independent reflections, R1 = 4.3%, wR2 = 6.0%, Z = 4). The crystal structures contain two independent M₂O₇^6? anions, one in a staggered, and the other in an ecliptic conformation. The cationic partial structure may be described as a distorted bcc arrangement of Ag⁺ and M⁴⁺. Comparison of the structures with respect to the Ag? Ag separations reveals the latter to be probably due to intrinsic d¹⁰–d¹⁰ bonding interactions as far as the range of 2.89 Å to 3.25 Å is considered.     

THE CRYSTAL AND MOLECULAR STRUCTURE OF RUBIDIUM BIS(PYRIDINE-2,6-DICARBOXYLATO)-CHROMATE(III)

Abstract

A three dimensional X-ray structural analysis of rubidium bis (pyridine-2,6-dicarboxylato)chromate(III), Rb[Cr(dipic)₂], has been carried out. The structure was refined by full matrix least-squares methods, using 713 observed independent reflections recorded at room temperature, to a conventional weighted R of 0.034. The crystals are tetragonal with a=b=6.950(3) Å, c=29.47(1) Å, space group 14 1/a and Z=4. The point group symmetry of the [Cr(dipic)₂]^? ion is S₄. The Cr–N and Cr–O distances (1.974(4) and 2.000(3) Å respectively) noticeably differ from the usual values in aminoacid chromium(III) complexes. The π bonding effect of the pyridine nitrogen atom corroborates the previous spectral studies on the sodium salt of this complex. The lability of [Cr(dipic)₂]^? in acid solution has been tentatively explained on the basis of the relatively severe strain within the complex ion.     

Strukturuntersuchungen an den Oxidnitriden SrTaO2N,CaTaO2N und LaTaON2 mittels Neutronen‐ und Röntgenbeugung

Structural Investigations on the Oxidenitrides SrTaO₂N, CaTaO₂N and LaTaON₂ by Neutron and X‐ray Powder Diffraction The crystal structures of the perovskite related oxidenitrides SrTaO₂N, LaTaON₂ and CaTaO₂N have been determined with special regard to the structures of the respective anionic partial structure. The structure refinements were performed by individual Rietveld analyses of both X‐ray and neutron powder diffractograms and in addition by joint refinements in order to confirm the results. Both refinement methods yield consistent structure solutions. At least the first two compounds have fully ordered anionic sublattices. The crystal structure of SrTaO₂N has been solved in the space group I4/mcm (a = 5.7049(3) Å, c = 8.0499(5) Å, R_p = 0.0706, R_wp = 0.0904, reflections: 70 (neutrons)/36 (X‐ray), R(F²)(n) = 0.147, R(F²)(X) = 0.0952), with an ordered anionic partial structure. LaTaON₂ crystallizes monoclinic (C2/m, a = 8.0922(3) Å, b = 8.0603(2) Å, c = 5.7118(2) Å, β = 134.815(1)°, R_p = 0.0592, R_wp = 0.0766, reflections: 235(n)/113(X), R(F²)(n) = 0.0944, R(F²)(X) = 0.165) and also shows a totally ordered distribution of the anions. In the case of CaTaO₂N (Pnma, a = 5.6239(3) Å, b = 7.8954(4) Å, c = 5.5473(3) Å, R_p = 0.0503, R_wp = 0.0656, reflections 206(n)/110(X), R(F²)(n) = 0.0985, R(F²)(X) = 0.0405) slightly unbalanced displacement parameters (neutron data, ordered O/N distribution model) hint at a partial exchange of oxygen and nitrogen.     

Beiträge zum Koordinationsverhalten von Oxidionen in anorganischen Feststoffen. III [1] Mn2P2O7, Mn2P4O12 und Mn2Si(P2O7)2 — Kristallzüchtung,Strukturverfeinerungen und Elektronenspektren von Mangan(II)‐Phosphaten

Contributions on the Bonding Behaviour of Oxygen in Inorganic Solids. III [1] Mn₂P₂O₇, Mn₂P₄O₁₂ und Mn₂Si(P₂O₇)₂ — Crystal Growth, Structure Refinements and Electronic Spectra of Manganese(II) Phosphates By chemical vapour transport reactions in a temperature gradient single crystals of Mn₂P₂O₇ (1050 → 950 °C) and Mn₂P₄O₁₂ (850 → 750 °C) have been obtained using P/I mixtures as transport agent. Mn₂Si(P₂O₇)₂ was crystallized by isothermal heating (850 °C, 8d; NH₄Cl as mineralizer) of Mn₂P₄O₁₂ und SiO₂. In Mn₂Si(P₂O₇)₂ [C 2/c, a = 17.072(1)Å, b = 5.0450(4)Å, c = 12.3880(9)Å, β = 103.55(9)°, 1052 independent reflections, 97 variables, R1 = 0.023, wR2 = 0.061] the Mn²⁺ ions show compressed octahedral coordination (d¯_Mn—O = 2.19Å). The mean distance d¯_Mn—O = 2.18Å was found for the radially distorted octahedra [MnO₆] in Mn₂P₄O₁₂ [C 2/c, Z = 4, a = 12.065(1)Å, b = 8.468(1)Å, c = 10.170(1)Å, β = 119.29(1)°, 2811 independent reflections, 85 variables, R1 = 0.025, wR2 = 0.072]. Powder reflectance spectra of the three pink coloured manganese(II) phosphates have been measured. The spectra show clearly the influence of the low‐symmetry ligand fields around Mn²⁺. Observed d—d electronic transition energies and the results of calculations within the framework of the angular overlap model (AOM) are in good agreement. Bonding parameters for the manganese‐oxygen interaction in [Mn²⁺O₆] chromophors as obtained from the AOM treatment (B, C, Trees correction α, e_σ, e_π) are discussed.     

Synthesis and structure of the heterotrinuclear chromium-palladium clusters (RC5H4CrCl)2-(μ3S)(μ-SCMe3)2Pd(PPh3) with ferromagnetic exchange interactions over the CrSCr system

Reactions of (RC₅H₄)₂Cr₂(SCMe₃)₂S(I, R = H; II, R = Me) with (PPh₃)₂PdCl₂ in benzene at 20°C gives trinuclear complexes (RC₅H₄)₂Cr₂Cl₂(μ₃-S)(μ-SCMe₃)₂Pd(PPh₃)(III, R = H; IV, R = Me). The structure of IV as a monobenzene solvate is established by an X-ray analysis (black-green triclinic crystals space group P$\text{1}$ with a = 11.403(4), b = 14.933(5), c = 14.131(5) Å, α = 99.13(3), β = 112.72(3), γ = 95.65(3)°, V = 2201.6 Å, Z = 2; IV·C₆H₆). The structure was solved by direct methods and refined in an anisotropic approximation to R = 0.046, R_w = 0.058 for 7643 reflections with I ? 2σ(I). In the molecule of IV metal atoms are separated by non-bonding distances (Cr … Cr 4.079(I), Cr … Pd 3.230(I) and 3.380(I) Å) but linked by the bridging tridentate sulphur atom (CrS 2.339(2) and 2.329(2), PdS 2.327(2) Å), and two SCMe₃ groups between Pd and Cr (CrS 2.396(2) and 2.403(2), PdS 2.350(2) and 2.381(2) Å, Cr?Pd 85.14(6) and 89.92(6)°). The Cl atoms are transferred from Pd to Cr atoms (CrCl 2.308(2) Å) and being terminally coordinated are in trans-positions to each other (as well as η-CH₃C₅H₄ rings) with respect to the Cr₂Pd plane. Cr atoms in III and IV exhibit ferromagnetic exchange interactions over the Cr?Cr system (+2J = 28 and 11 cm^?1, respectively).     

Synthesis and Characterization of ASnOAsO4(A = K and Rb)

Crystals of two alkali-metal tin(IV) arsenates, KSnOAsO₄ and RbSnOAsO₄, were grown from a flux and structurally characterized by single-crystal X-ray diffraction. Crystal data: RSnOAsO₄, orthorhombic, Pna2₁ (No. 33), a = 13.406(3) Å, b = 6.678(1) Å, c = 10.921(2) Å, Z = 8, R = 0.037 for 1173 independent reflections with I > 2.5ó(l); RbSnOAsO₄, as above except a = 13.567(3) Å, b = 6.791( 1) Å, c = 10.891(2) Å, R = 0.035 for 1958 independent reflections. The two compounds are isostructural with the nonlinear optical material KTiOPO₄. The oxygen frameworks of both tin compounds approximate closely to a centrosymmetric arrangement, as indicated from the analysis of atomic coordinates. Second harmonics were generated in powdered RbSnOAsO₄ to confirm the absence of a center of symmetry in the structure.     

Rhenium(V) Complexes of N,N′-Ethylenebis(2-mercaptopropanamide). Synthesis,Characterization, and X-ray Crystal Structures

The preparation of benzoyl-protectcd N,N′-ethylenebis(2-mercaptopropanamide) (H₄emp) and its ligand-exchange reaction with ReO₂(en)₂Cl are described. Three diastereomers, [syn-ReO(meso-emp)]; [anti-ReO(meso-emp)]-, and a pair of cnantiomers, [ReO(rac-emp)]-, were formed due to syn and anti orientation of the two methyl groups of the ligand relative to the ReO core. The diastereomers were separated by reverse phase C₁₈ semipreparative HPLC and isolated as salts of [Ph₄As][ReO-(emp)]. The structures of [Ph₄ As][ReO(meso-emp)] were determined by single-crystal X-ray analyses. [Ph₄As][syn-ReO(mesocmp)]H₂O crystallizes in triclinic space group Pl with a = 10.326(3) Å, b = 13.672(4) A, c = 14.023(5) Å, α = 61.20(2)°, β =74.74(3)°, γ= 75.68(2)° V = 1656.6(8) ų, Z = 2, Dc = 1.676 gmL^?1, F(000) = 824 and R = 0.0329 for 5877 unique reflections. For (he complex [Ph₄As][anti-ReO(meso-emp)], the crystal data are: monoclinic, space group P2₁/n, a = 9.128(2) Å, b = 24.284(7) Å, c = 14.112(4) Å, β = 93.41(2)° V = 3122.5(15) À³, Z = 4, Dc = 1.740 gmL^?1, F(000) = 1608 and R = 0.0361 for 5487 unique reflections. In both structures the rhenium atom is penta-coordinated and in an approximately square pyramidal environment.     

Deprotonierte Dithiocarbaminsäureester als Thiolat-S-Donor-Liganden. Strukturen von Ph(H)NC(S)SMe,Co(PhNC(S)SMe)3 und Cu6(PhNC(S)SMe)6

Deprotonated Dithiocarbamic Acid Esters as Thiolate S-Donor Ligands. Structures of Ph(H)NC(S)SMe, Co(PhNC(S)SMe)₃, and Cu₆(PhNC(S)SMe)₆ The reaction of N-phenyl-S-methyldithiocarbamate, PhN(H)C(?S)SMe, ( 1 ) with cobalt(II) and copper(II) salts yields the monomeric compound Co^III(PhNC(S)SMe)₃ ( 2 ) and the hexameric compound Cu₆^I(PhNC(S)SMe)₆ ( 3 ). These complexes contain the negatively charged imino-thiolate ligand PhN?C(? S)SMe, which has been formed by deprotonation of 1 . The crystal structures of 1 – 3 have been determined. 1 forms centrosymmetrical dimers through N? H …? S bridge bonds, the conformation in the solid state and in solution is Z,E′. Co^III shows in 2 a trigonal-antiprismatic coordination, with the ligands acting as N,S-chelates. 3 contains an octahedral Cu₆-core with Cu …? Cu-distances ranging from 276.3(5) to 305.7(4) pm. Each copper center is trigonally coordinated to one nitrogen and two sulfur atoms of three different ligands. Crystal data: 1 , triclinic, space group P1 , a = 590.5(6), b = 869.0(1), c = 968.5(9) pm, α = 67.29(8), β = 78.44(8), γ = 81.64(9)°, Z = 2, 1 775 reflections, R(R_w) = 0.0317(0.032). 2 , orthorhombic, space group Pbca, a = 978.0(2), b = 1 842.9(4), c = 3 059.7(6) pm, Z = 8, 1 129 reflections, R(R_w) = 0.0997(0.0886). 3 , monoclinic, space group P2₁/c, a = 1 363.1(3), b = 1 342.8(3), c = 1 671.9(3) pm, β = 103.48°, Z = 2, 1 374 reflections, R(R_w) = 0.0708(0.0617).