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1.
Synthesis and Structure Analysis of (tBuP)4Sn(CH3)2 and (CH3)2Sn[(tBu)P? P(tBu)]2Sn(CH3)2 The diphosphides K2[(tBu)P? (tBuP)2? P(tBu)] 7 or K2[(tBu)P? P(tBu)] 8 react with (CH3)2SnCl2 in a molar ratio of 1 : 1 to form the binary 5-membered ring system P4Sn 4 a and the 6-membered ring system Sn(P2)2Sn 5 a respectively. When (CH3)2SnCl2, however, is treated with 8 in a molar ratio of 2 : 1 the 4-membered ring system P3Sn 2 a is formed which includes the fragmentation of the intermediate K2[(CH3)2Sn ((tBu)P? P(tBu))2] 9. 4 a and 5 a could be obtained in a pure form and characterized NMR spectroscopically and by X-ray structure analyses; 2 a was identified only NMR spectroscopically.  相似文献   

2.
Synthesis of the Stannatetraphospholanes (tBuP)4SnR2 (R = tBu, nBu, C6H5) and (tBuP)4Sn(Cl)nBu Molecular and Crystal Structure of (tBuP)4Sn(tBu)2 The reaction of the diphosphide K2[tBuP-(tBuP)2-PtBu] 4 with the halogenostannanes (tBu)2SnCl2, (nBu)2SnCl2, (C6H5)2SnCl2 or nBuSnCl3 in a molar ratio of 1 : 1 leads via a [4 + 1]-cyclocondensation reaction to the stannatetraphospholanes (tBuP)4SnR2 3 b–3 d and (tBuP)4Sn(Cl)nBu 3 e , respectively, with the binary 5-membered P4Sn ring system. 3 b was characterized by a single crystal structure analysis; the 5-membered ring exists in a planar conformation. The compounds 3 b–3 e were identified by NMR and also by mass spectroscopy; the 31P{1H}-NMR spectra of 3 b–3 d showed an AA′MM′ (AA′MM′X), 3 e on the other hand an ABCD (ABCDX) spin system.  相似文献   

3.
Vibrational Spectra of Trimethylphosphonium Cations (CH3)3PX+ (X = H, D) and Crystal Structures of (CH3)3PD+SbCl6? and (CH3)3PCl+SbCl6? The trimethylphosphonium salts (CH3)3PX+SbCl6? (X = H, D) and (CH3)3PH+MF6? (M = As, Sb) are prepared and characterized by vibrational and NMR spectroscopy (1H, 31P, 13C). In addition the crystal structures of (CH3)3PD+SbCl6? and (CH3)3PCl+SbCl6? are reported. (CH3)3PD+SbCl6? crystallizes in the orthorhombic space group Pnma with a = 1555(1) pm, b = 753.1(8) pm, c = 1166(1) pm Z = 4. (CH3)3PCl+SbCl6? crystallizes triclinic in the space group P1 with a = 704.6(4) pm, b = 729.5(3) pm, c = 1391.1(7) pm, α = 89.57(4)°, b? = 88.04(4)°, γ = 74.98(4)° and Z = 2.  相似文献   

4.
Syntheses and Crystal Structure Analyses of [SbI3(SbMe3)(THF)]2 and [Li(THF)4]2[Bi2Cl8(THF)2] The reaction of Me3Sb with SbI3 in tetrahydrofuran (THF) gives [SbI3(SbMe3)(THF)]2 ( 1 ). [Li(THF)4]2[Bi2Cl8(THF)2] ( 2 ) is formed by reaction of LiCl and BiCl3 in tetrahydrofuran. The structures of ( 1 ) and ( 2 ) have been determined by X-ray diffractometry. Both structures contain centrosymmetric dimers with the geometry of edge sharing octahedra.  相似文献   

5.
Formation and Reaction of the Phosphanylidene-phosphorane (tBu)2P? P = PX(tBu)2 (X = Br, Cl) The formation of (tBu)2P? P = P(Br)tBu2 1 from [(tBu)2P]2PLi and BrH2C? CH2Br begins with an exchange of Li against Br and is then determined by the migration of Br from the secondary P atom in [(tBu)2P]2PBr 6 to the primary P in 1 . Similarly, (tBu)2P? P = PC1(tBu)2 2 is obtained starting from PCl3 and LiP(tBu)2. The formation of Phospanylidene—phosporane is not influenced by the choice o the halogene substituent, but the presence of the tBu groups is strongly required. (tBu)2P? P(Li)? P(SiMe3)2 e. g., yields (tBu)2P? P(br)? P(SiMe3)2 with BrH2C? CH2Br; however neither this nor (tBu)2P? P(Cl)? P(SiMe3)2 do rearrange to a Phosphanylidene-phosphorane. The F3C substituent could be neglected in this investigation as [(F3C)2P]2P? SiMe3 cannot be lithiated by means of BuLi. Compounds 1 and 2 display a charateristic temperature dependent behavior. While 1 at +20°C decomposes via the reactive intermediate (tBu)2P? P to from the cyclophosphanes P3[P(tBu)2]4, it gives crystals of [(tBu)2P]2P? p[P(tBu)2]2 at ?20°C (from a solution in toluene). Reacting 1 with tBuLi produces (tBu)2P? P = P(H)tBu2 20 and (tBu)2P? P(H)? P(tBu)2 14 . Initially, a transmetallation yield tBuBr and (tBu)2 P? P=Pli(tBu)2 21 ,then LiBr and isobutene are eliminated and 20 is formed which can rearrange to produce 14 . Without the elimination of isobutene, 1 react with nBuLi to give 21 witch can be trapped with Me3SiCl as (tBu)2P? P(tBu)2 23 . The main product in in this reaction is however [(tBu)2P]2P? nBu 22 .  相似文献   

6.
Phosphorane Iminato Complexes of Sulfur. Synthesis and Crystal Structures of [SO(Cl)(NPPh3)], [SO2(Cl)(NPPh3)], and [SCl(NPPh3)2]Cl The title compounds have been prepared by the reaction of Me3SiNPPh3 with SOCl2, SO2Cl2, and SCl2, respectively. They form colourless, moisture sensitive crystals, which were characterized by IR spectroscopy and by crystal structure determinations. [SO(Cl)(NPPh3)]: Space group P21/n, Z = 4, structure determination with 2 434 observed unique reflections, R = 0.047. Lattice dimensions at 19°C: a = 1 304.8, b = 996.5, c = 1 339.5 pm, β = 93.75°. The compound forms monomeric molecules with a remarkably long S? Cl bond of 234.2 pm and distances SN and PN of 154.6 and 161.6 pm, respectively, which agree with double bonds. [SO2(Cl)(NPPh3)]: Space group P21/n, Z = 4, structure solution with 2 872 observed, unique reflections, R = 0.047. Lattice dimensions at 20°C: a = 956.9, b = 1 909, c = 1 002.0 pm, β = 106.06°. The compound forms monomeric molecules with distances S? Cl of 207.1 pm, SN of 154.5 pm, and PN of 161.6 pm. [SCl(NPPh3)2]Cl: Space group P21/c, Z = 4, structure solution with 5 224 observed, unique reflections, R = 0.042. Lattice dimensions at 20°C: a = 1 108.6, b = 1 603.8, c = 1 840.5 pm, β = 99.98°. The compound forms ions [SCl(NPPh3)2]+ and Cl?. In the cation the sulfur atom is φ-tetrahedrally coordinated with a long S? Cl distance of 248.5 pm and SN bond lengths of 154.5 and 156.0 pm.  相似文献   

7.

New rhenium oxo-complexes [ReOX3(OAsPh3)(AsPh3)] (X = Cl and Br) have been synthesised and characterised by X-ray diffraction, IR, electronic and magnetochemical measurements. They were obtained in high yield in reactions between [ReOX3(AsPh3)2] and acetonitrile in air.  相似文献   

8.
Synthesis of the Silatetraphospholanes (tBuP)4SiMe2, (tBuP)4SiCl2, and (tBuP)4Si(Cl)SiCl3 Molecular and Crystal Structure of (tBuP)4SiCl2 The reaction of the diphosphide K2[(tBuP)4] 7 with the halogenosilanes Me2SiCl2, SiCl4 or Si2Cl6 in a molar ratio of 1:1 leads via a [4 + 1]-cyclocondensation reaction to the silatetraphospholanes (tBuP)4SiMe2 1,1-dimethyl-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 1 , (tBuP)4SiCl2, 1,1-dichloro-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 2 , and (tBuP)4Si(Cl)SiCl3, 1-chloro-1-trichlorsilyl-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 3 , respectively, with the 5-membered P4Si ring system. The reaction leading to 1 is accompanied with the formation of the by-product Me2(Cl)-Si–(tBuP)4–Si(Cl)Me2 1a (5:1), which has a chain structure. On warming to 100°C 1a decomposes to 1 and Me2SiCl2. The compounds 2 and 3 do not react further with an excess of 7 due to strong steric shielding of the ring Si atoms by the t-butyl groups. 1, 2 and 3 could be obtained in a pure form and characterized NMR spectroscopically; 2 was also characterized by a single crystal structure analysis. 1a was identified by NMR spectroscopy only.  相似文献   

9.
Metal Ampoules as Mini‐Autoclaves: Syntheses and Crystal Structures of [Al(NH3)4Cl2][Al(NH3)2Cl4] and (NH4)2[Al(NH3)4Cl2][Al(NH3)2Cl4]Cl2 The salts [Al(NH3)4Cl2]+[Al(NH3)2Cl4]≡AlCl3 · 3 NH3 ( 1 ) and (NH4+)2[Al(NH3)4Cl2]+[Al(NH3)2Cl4](Cl)2≡ AlCl3 · 3 NH3 · (NH4)Cl ( 2 ) have been obtained as single crystals during the reactions of aluminum and aluminum trichloride, respectively, with ammonium chloride in sealed Monel metal containers. The crystal structure of 1 was determined again [triclinic, P‐1; a = 574.16(10); b = 655.67(12); c = 954.80(16) pm; α = 86.41(2); β = 87.16(2); γ = 84.89(2)°], that of 2 for the first time [monoclinic, I2/m; a = 657.74(12); b = 1103.01(14); c = 1358.1(3) pm; β = 103.24(2)°].  相似文献   

10.
Oxidative Fluorination of (CF3)(R) (R = CF3, Cl) and the Crystal Structure of (CF3)(Cl) F+ AsF6? Oxidative fluorination of (CF3)(R) (R = CF3, Cl) with XeF+MF6? (M = As, Sb) in anhydrous HF results in formation of monofluorsulfonium hexafluorometalates. The salts are characterized by vibrational, NMR, and mass spectra. (CF3)(Cl)F+ AsF6? crystallizes in the monoclinic space group P21/c with a = 9.955(10) Å, b = 11.050(5) Å, c = 12.733(15) Å, β = 97.77(5)°, and Z = 4.  相似文献   

11.
Phosphoraneiminato Complexes of Boron. Syntheses and Crystal Structures of [BBr2(NPMe3)]2, [B2Br3(NPiPr3)2]Br, [B2(NPEt3)4]Br2, [B2Br2(NPPh3)3]BBr4 and [{B2(NMe2)2}2(NPEt3)2]Cl The bromoderivatives of the title compounds are prepared from the corresponding silylated phosphoraneimines Me3SiNPR3 and boron tribromide. The boron subcompound [{B2(NMe2)2}2(NPEt3)2]Cl2 derives from Me3SiNPEt3 and B2Cl2(NMe2)2. All complexes are characterized by NMR and IR spectroscopy as well as by crystal structure determinations. [BBr2(NPMe3)]2 (1): Space group P21/n, Z = 2, R = 0.031. Lattice dimensions at ?50°C: a = 723.8, b = 894.2, c = 1305.4 pm, β = 92.35°. 1 forms centrosymmetric molecules in which the boron atoms are linked via μ2-N bridges of the NPMe3? groups of from B2N2 four-membered rings with B? N distances of 149.9 and 150.9 pm. B2Br3(NPiPr3)2]Br (2): Space group P21, Z = 2, R = 0.059. Lattice dimensions at ?80°C: a = 817.6, b = 2198.7, c = 851.5 pm, β = 115.09°. In the cations of 2 the boron atoms are lined via the μ2-N atoms of the NPiPr3? groups to form planar, asymmetric B2N2 four-membered rings with B? N distances of 143 and 156 pm. [B2(NPEt3)4[Br2·4CH2Cl2 (3): Space group C2/c, Z = 4, R = 0.042. Lattice dimensions at ?50°C: a = 1946.1, b = 1180.3, c = 2311.3 pm, β = 101.02°. The structure contains centrosymmetric dications in which both the boron atoms are lined by the N atoms of two of the NPEt3? groups to form a B2N2 four-membered ring with B? N distances of 149.6 pm. The remaining two NPEt3? groups are terminally bonded with very short B? N distances of 133.5 pm. B2Br2(NPPh3)3]BBr4 (4): Space group P1 , Z = 2, R = 0.065. Lattice dimension at ?50°C: a = 1025.7, b = 1496.1, c = 1807.0 pm, α = 85.09°, β = 82.90°, γ = 82.72°. In the cation the boron atoms are lined via the μ2-N atoms of two of the NPPh3? groups to form a nearly planer B2N2 four-membered ring with B? N distances of 149.3-153.1 pm. The third NPPh33 group is terminally connected with teh sp2 hybridized boron atom and with a B? N distance of 134.1 pm along with an almost linear BNP bond angle of 173.6°. [{B2(NMe2)2}2(NPEt2)2]Cl2 · 3CH2Cl2 (5): Space group C2/c, Z = 4, R = 0.098. Lattice dimensions at ?70°C: a = 1557.9, b = 1294.7, c = 2122.9 pm, β = 96.08°. The structure of 4 contains centrosymmetric dications in which two by two B-B dumb-bells are linked via the μ2-N atoms of the two NEPt3? groups to form B4N2 six-membered rings with B? N distances of 150 and 156 pm and B-B distances of 173 pm. The B? N distances of the terminally bonded NMe2? groups correspond to 138 pm double bonds.  相似文献   

12.
Vibrational Spectra and Normal Coordinate Analysis of (CF3)2PX and (CF3)2AsX (X = F, Cl, Br, I) Gas phase i. r. spectra and liquid-phase Raman spectra of (CF3)2AsX are reported. The i. r. investigation of the corresponding phosphorus compounds is complited. The spectra of both the phosphorus and the arsenic compounds were assigned on the basis of a normal coordinate analysis using a transferred force field.  相似文献   

13.
Synthesis and Crystal Structures of (Ph3PNPPh3)2[Re2Br10] and (Ph4P)[Re2Br9] Depending on the molar ratio by reaction of [n-Bu4N]2[ReBr6] with the Lewis acid BBr3 in dichloromethane the bioctahedral complexes [n-Bu4N]2[Re2Br10] and [n-Bu4N][Re2Br9] are formed. The X-ray structure determination on (Ph3PNPPh3)2[Re2Br10] (monoclinic, space group C 2/c, a = 20.007(4), b = 15.456(5), c = 24.695(4) Å, β = 107.53(2)°, Z = 4) reveals a centrosymmetric edge-sharing complex anion with approximate D2h symmetry and mean terminal and bridging Re–Br bond lengths of 2.453 (equatorial), 2.482 (axial) and 2.591 Å, respectively, and a Re–Re distance of 3.880 Å. (Ph4P)[Re2Br9] (triclinic, space group P 1, a = 11.062(2), b = 12.430(3), c = 13.163(5) Å, α = 72.94(2), β = 68.47(2), γ = 82.09(2)°, Z = 2) contains a confacial bioctahedral anion with nearly D3h symmetry and mean terminal and bridging Re–Br distances of 2.460 and 2.536 Å, respectively, and a Re–Re distance of 2.780 Å.  相似文献   

14.
Heterometallic Coordination Compounds Re2(μ-PPh2)2[mer-(CO)3]2-trans-[InX2(H2O)]2 and New Halogene Containing Three- and Four-Nuclear Rhenium Clusters from Reactions between Re2(μ-PPh2)2(CO)8 and InX3 (X = Cl, Br, I) In sealed glass tubes equimolar amounts of Re2(μ-PPh2)2(CO)8 and InX3 (X = Cl, Br, I) were reacted in the presence of xylene at 220°C to two types of products. The first type comprised the heterometallic coordination compounds Re2(μ-PPh2)2(CO)6[InX2(H2O)]2 (X = Cl, Br, I) (yield 60%), and the second halogene containing rhenium complexes Re33-H)(μ3-X)(μ-PPh2)3(CO)6 (unsaturated three-membered metal ring with 46 VE) and Re4(μ-H)(μ-X)(μ-PPh2)44-PPh)(CO)8 and additionally those substances as cis-IRe(CO)4(PPh2H), Re2(μ-PPh2)(μ-X)(CO)8 (X = Cl, Br), Re2(μ-I)2[μ-(PPh2)2O](CO)6 and Re4(μ-Cl)2(μ-PPh2)44-PPh)(CO)8 (four-membered metal ring with 66 VE with three Re? Re bonds) which have been observed in one or two of the three reaction systems. A proposal of the reaction course is discussed. The single X-ray analysis of Re2(μ-PPh2)2[mer(CO)3]2-trans[InI2(H2O)]2 · 2 Me2CO shows for the two fold phosphido bridged dirhenium molecular fragment with 34 VE a Re? Re bond of 294.6(1) pm. From two possible transpositions of both In? Re bond vectors, the one found advantageously has sterical reasons. The average In? Re single bond length is 271.1(1) pm. The corresponding determination of the unsaturated three-membered ring compound Re33-H) (μ3-Cl)(μ-PPh2)3(CO)6 showed three Re? Re bond lenghts of comparable size, of which the mean value of 281.9(1) pm was significantly shortened by π electron delocalization effect compared to that of a saturated phosphido bridged three-membered rhenium ring compound. As it was recognized by further comparison, the structural data of the common molecular fragments in the three examined three-membered rhenium ring clusters (X = Cl, Br, I) are not dependent on the different kind of halogeno ligand atoms. Finally, the crystal structure determination of the substance Re4(μ-H)(μ-Br)(μ-PPh2)44-PPh)(CO)8 shows the presence of square-pyramidal Re44-P) atomic arrangement, of which the planar basic plane has a sequence of up- and downwards orientated four diphenylphosphido bridging groups. The four measured Re? Re single bond lengths (mean value 302.7(3) pm change with the different kind of bridging atoms. The structural features observed are compared with those of a corresponding iodine derivative.  相似文献   

15.
Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XIX. [Co4P2(PtBu2)2(CO)8] and [{Co(CO)3}2P4tBu4] from Co2(CO)8 and tBu2P–P=P(Me)tBu2 Co2(CO)8 reacts with tBu2P–P=P(Me)tBu2 yielding the compounds [Co4P2(PtBu2)2(CO)8] ( 1 ) and [{η2tBu2P=P–P=PtBu2}{Co(CO)3}2] ( 2 a ) cis, ( 2 b ) trans. In 1 , four Co and two P atoms form a tetragonal bipyramid, in which two adjacent Co atoms are μ2‐bridged by tBu2P groups. Additionally, two CO groups are linked to each Co atom. In 2 a and 2 b , each of the Co(CO)3 units is η2‐coordinated to the terminal P2 units resulting in the cis‐ and trans‐configurations 2 a and 2 b . 1 crystallizes in the orthorhombic space group Pnnm (No. 58) with a = 879,41(5), b = 1199,11(8), c = 1773,65(11) pm. 2 a crystallizes in the monoclinic space group P21/n (No. 14) with a = 875,97(5), b = 1625,36(11), c = 2117,86(12) pm, β = 91,714(7)°. 2 b crystallizes in the triclinic space group P 1 (No. 2) with a = 812,00(10), b = 843,40(10), c = 1179,3(2) pm, α = 100,92(2)°, β = 102,31(2)°, γ = 102,25(2)°.  相似文献   

16.
New mixed-ligand copper(I) complexes, [Cu(Phca2en)(PPh3)X], [Phca2en = N,N′-bis(β-phenylci-nnamaldehyde)-1,2-diiminoethane and X=Cl (1), Br (2), I (3), NCS (4), N3 (5)] have been synthesized and characterized by various techniques. 1H and 13C-NMR and IR spectral data of these copper(I) complexes are compared with the free ligand to elucidate some structural features. The structures of [Cu(Phca2en)(PPh3)Br] (2) and [Cu(Phca2en)(PPh3)I] (3) have been determined from single-crystal data showing that the coordination geometry around copper atom is a distorted tetrahedron. Furthermore, these Cu(I) complexes exhibit supramolecular motifs of the type multiple phenyl embraces resulting from attractive interactions between phenyl rings of PPh3 moieties. The presence of the C–H…Cu weak intramolecular hydrogen bonds, due to the trapping of C–H bonds in the vicinity of the metal atoms, is also reported.  相似文献   

17.
Halogen Exchange at Re3-Clusters: A New Synthetic Route to Binary and Ternary Rhenium(III) Bromides. Crystal Structures of Cs2[Re3Br11] and Cs3[Re3Br3Cl9] The substitution of “inner” ligands in transition metal clusters in aqueous HX solutions is hitherto unknown. For the first time the substitution of bridging and terminal chloride for bromide ions was observed at rhenium clusters, [Re3(μ-Cli,b)3(Cl)(Cli,t)(3?x)(H2Oi,t)x](3?x)? (x = 0–3), via the reaction of “ReCl3 · 2 H2O” in hot hydrobromic acid solution under an inert gas atmosphere. This establishes a new synthetic route to ternary Re(III) bromides as well as to ReBr3. However, ternary Re(IV) bromides, A2ReBr6 (A = Rb, Cs), are dominating in the presence of oxygen, rhenium(III) bromides are only by-products. Dark brown rods of Cs2[Re3Br11] are obtained from argon saturated, hot hydrobromic acid solutions of “ReCl3 · 2 H2O” and CsBr. The crystal structure (orthorhombic, Pnma (Nr. 62); a = 955.51(5); b = 1 610.29(10); c = 1 372.70(9); Z = 4; Vm = 318.0(2) cm3mol?1; R = 0.084, Rw = 0.058) consists of defect clusters [Re3BrBrBr□i,t]2? in which one in plane, terminal position is not occupied. The substitution of “inner” ligands has been observed in the case of chloride for bromide only, the Bri,b and Ii,b ligands in ReBr3 and ReI3, respectively, are not substituted in hydrochloric acid even at temperatures as high as 100°C. Bordeaux red square pyramids of CsReBrCl3 = Cs3[Re3(μ-Bri,b)3ClCl] are obtained from hot hydrochloric acid solutions of ReBr3 · 2/3 H2O upon evaporation. CsReBrCl3 (orthorhombic, C2cm (Nr. 40); a = 1 419.0(1); b = 1 419.2(1); c = 1 080.30(8) pm; Z = 4; Vm = 327.6(3) cm3mol?1; R = 0.033, Rw = 0.028) is isostructural to the corresponding chloride CsReCl4.  相似文献   

18.
Vibrational Raman Spectra of Hexahalo Complexes of OsIV (X = Cl, I) and IrIV (X = Cl, Br) at 80 K The Resonance-Raman (RR) spectra of the tetrabutyl- resp. tetraethylammonium salts of [OsCl6]2?, [OsI6]2?, [IrCl6]2?, and [IrBr6]2? have been investigated with the excitation-lines of an Ar+ and Kr+ laser. Devices with a movable sample holder for low-temperature experiments (80 K) are described. The anormal intensities of some of the Ra-active fundamentals are attributed to the RR effect. As a rule the deformation vibration υ5(T2g) is RR enhanced if excited within a π—π*(dt2g)-CT-transition and the stretching vibration υ2(Eg) is RR-enhanced within a π—σ*(deg)-CT-transition. The dispersion of the degree of depolarisation of the three Ra-active fundamentals of [IrBr6]2? demonstrates, that this rule cannot only be applicated to the symmetrical but also to the antisymmetrical part of the scattering tensor.  相似文献   

19.
Preparation of the Nonahalogenodiplatinates(IV), [Pt2X9]?, X ? Cl, Br Spectroscopic Characterization, Normal Coordinate Analysis, and Crystal Structure of (PPN)[Pt2Br9] On heating the tetrabutylammonium salts (TBA)2[PtX6], with trifluoroacetic acid the nonahalogenodiplatinates(IV) (TBA)[Pt2X9], with X ? Cl, Br are formed. The X-ray structure determination on (PPN)[Pt2Br9] (orthorhombic, space group Pca2, Z = 4) shows for the anions pairs of face-sharing octahedra with nearly D3h symmetry. The mean terminal and bridging Pt? Br bond lengths are determined to be 2.42 and 2.52 Å, respectively. The electrostatic interaction of the Pt atoms results in the Pt? Pt distance of 3.23 Å and an elongation as it has been forecasted by the MO scheme for d6 systems. Using the structural data a normal coordinate analysis based on a general valence force field for [Pt2Br9]? has been performed, revealing a good agreement of the calculated frequencies with the bands observed in the IR and Raman spectra. The stronger bonding of the terminal as compared to the bridging ligands is shown by the valence force constants, fa(Br1) = 1,55 > fd(Brb) = 0,93 mdyn/ Å.  相似文献   

20.
Synthesis and Crystal Structures of (PPh4)2[TeS3] · 2 CH3CN and (PPh4)2[Te(S5)2] (PPh4)2[TeS3] · 2 CH3CN was obtained by the reaction of PPh4Cl, Na2S4 and Te in acetonitrile. With sulfur it reacts yielding (PPh4)2[Te(S5)2]. The crystal structures of both products were determined by X-ray diffraction. (PPh4)2[TeS3] · 2 CH3CN: triclinic, space group P1 , Z = 2, R = 0.041 for 4 629 reflexions; it contains trigonal-pyramidal [TeS3]2? ions with an average Te? S bond length of 233 pm. (PPh3)2[Te(S5)2]: monoclinic, P21/n, Z = 2, R = 0.037 for 2 341 reflexions. In the [Te(S5)2]2? ion the tellurium atom has a nearly square coordination by four S atoms. Along with the Te atoms each of the two S5 groups forms a ring with chair conformation.  相似文献   

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