首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 730 毫秒
1.
Wu Y  Bensch W 《Inorganic chemistry》2008,47(17):7523-7534
Four new quaternary alkali neodymium thiophosphates K 9Nd[PS 4] 4 ( 1), K 3Nd[PS 4] 2 ( 2), Cs 3Nd[PS 4] 2 ( 3), and K 3Nd 3[PS 4] 4 ( 4) were synthesized by reacting Nd with in situ formed fluxes of K 2S 3 or Cs 2S 3, P 2S 5 and S in appropriate molar ratios at 973 K. Their crystal structures are determined by single crystal X-ray diffraction. Crystal data: 1: space group C2/ c, a = 20.1894(16), b = 9.7679(5), c = 17.4930(15) A, beta = 115.66(1) degrees , and Z = 4; 2: space group P2 1/ c, a = 9.1799(7), b = 16.8797(12), c = 9.4828(7) A, beta = 90.20(1) degrees , and Z = 4; 3: space group P2 1/ n, a = 15.3641(13), b = 6.8865(4), c = 15.3902(13) A, beta = 99.19(1) degrees , and Z = 4; 4: space group C2/ c, a = 16.1496(14), b = 11.6357(7), c = 14.6784(11) A, beta = 90.40(1) degrees , and Z = 4. The structure of 1 is composed of one-dimensional (1) infinity{Nd[PS 4] 4} (9-) chains and charge balancing K (+) ions. Within the chains, eight-coordinated Nd (3+) ions, which are mixed with K (+) ions, are connected by [PS 4] (3-) tetrahedra. The crystal structures of 2 and 3 are characterized by anionic chains (1) infinity{Nd[PS 4] 2} (3-) being separated by K (+) or Cs (+) ions. Along each chain the Nd (3+) ions are bridged by [PS 4] (3-) anions. The difference between the structures of 2 and 3 is that in 2 the Nd (3+) ions are coordinated by four edge-sharing [PS 4] (3-) tetrahedra while in 3 each Nd (3+) ion is surrounded by one corner-sharing, one face-sharing, and two edge-sharing [PS 4] (3-) tetrahedra. The structure of 4 is a three-dimensional network with K (+) cations residing in tunnels running along [110] and [110]. The {Nd(1)S 8} polyhedra share common edges with four [PS 4] tetrahedra forming one-dimensional chains (1) infinity{Nd[PS 4] 2} (3-) running along [110] and [110]. The chains are linked by {Nd(2)S 8} polyhedra yielding the final three-dimensional network (3) infinity{Nd[PS 4] 2} (3-). The internal vibrations of both crystallographically independent [PS 4] (3-) anions of 2- 4 have been assigned in the range 200-650 cm (-1) by comparison of their corresponding far/mid infrared and Raman spectra (lambda exc = 488 nm) on account of locally imposed C 1 symmetry. In the Fourier-transform-Raman spectrum (lambda exc = 1064 nm) of 2- 4, very similar well-resolved electronic Raman (ER) transitions from the electronic Nd (3+) ground-state to two levels of the (4)I 9/2 ground manifold and to the six levels of the (4)I 11/2 manifold have been determined. Resonant Raman excitation via a B-term mechanism involving the (4)I 15/2 and (4)F 3/2 intermediate states may account for the significant intensity enhancement of the ER transitions with respect to the symmetric P-S stretching vibration nu 1. Broad absorptions in the UV/vis/NIR diffuse reflectance spectrum at 293 K in the range 5000-25000 cm (-1) of 2- 4 are attributed to spin-allowed excited quartet states [ (4)(I < F < S < G < D)] and spin-forbidden doublet states [ (2)(H < G < K < D < P)] of Nd (3+). A luminescense spectrum of 3 obtained at 15 K by excitation with 454.5 nm shows multiplets of narrow lines that reproduce the Nd (3+) absorptions. Sharp and intense luminescence lines are produced instead by excitation with 514.5 nm. Lines at 18681 ( (4)G 7/2), 16692 ( (4)G 5/2), 14489 ( (4)F 9/2), and 13186 cm (-1) ( (4)F 7/2) coincide with the corresponding absorptions. Hypersensitive (4)G 5/2 is split by 42 cm (-1). The most intense multiplet at about 16500 cm (-1) is assigned to the transition from (4)G 5/2 to the Stark levels of the ground manifold (4)I 9/2.  相似文献   

2.
The hexanuclear Pd6Cl12, i.e., the crystal phase classified as beta-PdCl2, was obtained by reacting [TBA]2[Pd2Cl6] with AlCl3 (or FeCl3) in CH2Cl2. The action of AlCl3 on PtCl42-, followed by digestion of the resulting solid in 1,2-C2H4Cl2 (DCE), CHCl3, or benzene, produced Pt6Cl12.DCE, Pt6Cl12.CHCl3, or Pt6Cl12.C6H6, respectively. Treating [TBA]2[PtCl6] with a slight excess of AlCl3 afforded [TBA][Pt2Cl9], whose anion was established crystallographically to be constituted by two "PtCl6" octahedra sharing a face. Dehydration of H2PtCl6.nH2O with SOCl2 gave an amorphous compound closely analyzing as PtCl4, reactive with [Q]Cl in SOCl2 to yield [Q][Pt2Cl9] or [Q]2[Pt2Cl10], depending on the [Q]Cl/Pt molar ratio (Q=TBA+, PPN+). A single-crystal X-ray diffraction study has shown [PPN]2[Pt2Cl10].C7H8 to contain dinuclear anions formed by two edge-sharing PtCl6 octahedra.  相似文献   

3.
By reaction of Na2[B9H9] with the appropriate N-halogenosuccinimide, the monohalogenated anion [1-XB9H8]2- (X = Cl, Br, or I) is formed. The X-ray diffraction analyses performed on single crystals of (Ph4P)2[1-XB9H8].CH3CN (X = Cl, Br, I) reveal that the tricapped trigonal prismatic geometry of the cluster is retained after substitution in the 1-position. Crystallographic data are as follows for (Ph4P)2[1-XB9H8].CH3CN. X = Cl, Br: monoclinic, space group P2(1), a = 10.7 A, b = 32.9 A, c = 13.8 A, beta = 96 degrees, Z = 4, R1 = 0.038 and R1 = 0.036, respectively. X = I: monoclinic, space group P2(1)/n, a = 10.5 A, b = 13.6 A, c = 33.4 A, beta = 94 degrees, Z = 4, R1 = 0.094. The compounds have been characterized by vibrational and 11B NMR spectroscopy as well.  相似文献   

4.
The reaction of UO2(NO3)2.6H2O with Co or Cu metal, phosphoric acid, and CsCl under mild hydrothermal conditions results in the formation of Cs2{(UO2)4[Co(H2O)2(HPO4)(PO4)4} (1) or Cs(3+x)[(UO2)3CuH(4-x)(PO4)5].H2O (2). The structure of 1 contains uranium atoms in pentagonal bipyramidal and hexagonal bipyramidal environments. The interaction of the uranyl cations and phosphate anions creates layers in the [ab] plane. The uranyl phosphate layers are joined together by octahedral Co centers wherein the Co is bound by phosphate and two cis water molecules. In addition, the Co ions are also ligated by a uranyl oxo atom. The presence of these octahedral building units stitches the structure together into a three-dimensional framework where void spaces are filled by Cs+ cations. The structure of 2 contains uranium centers in UO6 tetragonal bipyramidal and UO7 pentagonal bipyramidal geometries. The uranyl moieties are bridged by phosphate anions into sinusoidal sheets that extend into the [bc] plane and are linked into a three-dimensional structure by Cu(II). The Cu centers reside in square planar environments. Charge balance is maintained by Cs+ cations. Both the overall structures and the uranyl phosphate layers in 1 and 2 are novel.  相似文献   

5.
A novel Pd(II)-dibenzo-18-crown-6 (DB18C6) complex [K(DB18C6)]2[Pd(SCN)4] has been isolated and characterized by X-ray diffraction analysis. In the solid state, it displays a quasi-one-dimensional infinite chain of two [K(DB18C6)] + complex cations and a [Pd(SCN)4]2- anion bridged by K+-p interactions between adjacent [K(DB18C6)] + units.  相似文献   

6.
Cs[Me2GaF2], a Solvent-free Caesium Salt of the Plainest Diorganodifluoro Gallate The metalate Cs[Me2GaF2] ( 1 ), obtained by the reaction of Cs[Me3GaF] with H2O in THF and recrystallized from toluene, was characterized by an X-ray structure determination. According to the structure analysis, 1 consists of puckered layers of Cs[Me2GaF2] stacked along [001].  相似文献   

7.
Two quaternary silver selenoarsenates Cs3AgAs4Se8 (I) and CsAgAs2Se4 (II) have been discovered by methanothermal reaction of Li3AsSe3 with AgBF4 in the presence of the respective alkali metal sources Cs2CO3 and CsCl. Orange crystals of Cs3AgAs4Se8 (I) were formed after reaction at 120 degrees C for 72 h, whereas red CsAgAs2Se4 (II) was obtained under slightly different conditions at 140 degrees C for 70 h. Both compounds possess novel two-dimensional (2D) polyanions consisting of infinite 1 infinity[AsSe2]- chains that are interconnected by Ag+ ions in different coordination patterns. In I, a double layer of 1 infinity[AsSe2]- chains is bridged by distorted trigonal planar coordinated Ag+ atoms to form a 2 infinity[AgAs4Se8]3- layer with a thickness of about 11.3 A. The nonbonding Ag...Ag distances are about 4.220 A, and large cavities within the layers accommodate for three of the four crystallographic Cs+ cations. The double amount of Ag+ atoms per AsSe2 chain unit in II leads to simple layers 2 infinity[AgAs2Se4]- [=[Ag2As4Se8]2-] in which the Ag+ atoms are arranged in rows between the 1 infinity[AsSe2]- chains, with alternating Ag...Ag distances of 3.053(3) and 3.488(3) A. Hereby the 1 infinity[AsSe2]- polyanions show a disorder within the central (-As-Seb)- chain (b = bridging), while the positions of the terminal Se atoms (Set) remain unaffected. The thermal, optical, and spectroscopic properties of the compounds are reported. Both I and II melt with decomposition and are wide band gap semiconductors with values of 2.07 and 1.79 eV, respectively. Raman spectroscopic data show typical band patterns expected for infinite [AsSe2]- chains. Crystal Data: Cs3AgAs4Se8 (I), monoclinic, C2/c, a = 25.212(2) A, b = 8.0748(7) A, c = 22.803(2) A, beta = 116.272(2) degrees, Z = 8; CsAgAs2Se4 (II), monoclinic, P2(1)/n, a = 10.9211(1) A, b = 6.5188(2) A, c = 13.7553(3) A, beta = 108.956(1) degrees, Z = 4.  相似文献   

8.
The reaction of Ta with an in situ formed polythiophosphate melt of Cs2S3, P2S5, and S yields the two new quaternary tantalum thiophosphates Cs2Ta2P2S12 (I) and Cs4Ta4P4S24 (II). Both compounds were obtained with the same stoichiometric ratio but at different reaction temperatures. Compound I was prepared at 873 K and crystallizes in the monoclinic space group P2(1)/c (No. 14) with a = 8.862(2) A, b = 12.500(3) A, c = 17.408(4) A, beta = 99.23(3) degrees, and Z = 4. Compound II was prepared at 773 K and crystallizes in the monoclinic space group P2(1)/n (No. 14) with a = 14.298(3) A, b = 17.730(4) A, c = 16.058(3) A, beta = 106.19(3) degrees, and Z = 4. The two structures are closely related and exhibit two-dimensional anionic layers consisting of dimeric [Ta2S11] units which are linked by two tetradentate and two tridentate [PS4] tetrahedra. The significant difference between these two compounds is the orientation of the [Ta2S11] units in infinite [Ta2S4(PS4)]x chains which are subunits of both structures. The specific orientation of the [Ta2S11] blocks in compound I leads to the formation of one cavity in the 2(infinity)[Ta2P2S12]2- layers, whereas in compound II two types of cavities are observed in the 2(infinity)[Ta4P4S24]4- layers. The Cs+ ions are located between the layers above and below the cavities. The compounds were characterized with infrared spectroscopy in the MIR region, Raman spectroscopy, and UV/Vis diffuse reflectance spectroscopy. When Cs4Ta4P4S24 (II) is heated at the synthesis temperature of compound I it is fully converted into compound I.  相似文献   

9.
Russian Journal of General Chemistry - Palladium phosphonium complexes with mononuclear anions [Ph3PCH2CN][PdBr4], [Ph4P][PdBr4], and [Ph3PC5H9-cyclo][PdBr3(Et2SO)] were synthesized by the reaction...  相似文献   

10.
The cation-π interactions have attracted much attention as an important noncovalent binding force. We have synthesized and characterized the first example[K(DB 18C6)]2[Pd(SCN)4] which exist K+-π interactions in crown ether compounds[1]. However,the reported Na+ complexes structurally characterized by X-ray diffraction analysis have so far been limited to a few compounds. We now report the structure of complex:[Na(DB18C6)]2[Pd(SCN)4] which also exist Na+-n interactions.  相似文献   

11.
A series of heptametallic cyanide cages are described; they represent soluble analogues of defect-containing cyanometalate solid-state polymers. Reaction of 0.75 equiv of [Cp*Ru(NCMe)3]PF6, Et(4)N[Cp*Rh(CN)3], and 0.25 equiv of CsOTf in MeCN solution produced (Cs subset [CpCo(CN)3]4[Cp*Ru]3)(Cs subset Rh4Ru3). 1H and 133Cs NMR measurements show that Cs subset Rh4Ru3 exists as a single Cs isomer. In contrast, (Cs subset [CpCo(CN)3]4[Cp*Ru]3) (Cs subset Co4Ru3), previously lacking crystallographic characterization, adopts both Cs isomers in solution. In situ ESI-MS studies on the synthesis of Cs subset Rh4Ru3 revealed two Cs-containing intermediates, Cs subset Rh2Ru2+ (1239 m/z) and Cs subset Rh3Ru3+ (1791 m/z), which underscore the participation of Cs+ in the mechanism of cage formation. 133Cs NMR shifts for the cages correlated with the number of CN groups bound to Cs+: Cs subset Co4Ru4+ (delta 1 vs delta 34 for CsOTf), Cs subset Rh4Ru3 where Cs+ is surrounded by ten CN ligands (delta 91), Cs subset Co4Ru3, which consists of isomers with 11 and 10 pi-bonded CNs (delta 42 and delta 89, respectively). Although (K subset [Cp*Rh(CN)3]4[Cp*Ru]3) could not be prepared, (NH4 subset [Cp*Rh(CN)3]4[Cp*Ru]3) (NH4 subset Rh4Ru3) forms readily by NH4+-template cage assembly. IR and NMR measurements indicate that NH4+ binding is weak and that the site symmetry is low. CsOTf quantitatively and rapidly converts NH4 subset Rh4Ru3 into Cs subset Rh4Ru3, demonstrating the kinetic advantages of the M7 cages as ion receptors. Crystallographic characterization of CsCo4Ru3 revealed that it crystallizes in the Cs-(exo)1(endo)2 isomer. In addition to the nine mu-CN ligands, two CN(t) ligands are pi-bonded to Cs+. M subset Rh4Ru3 (M = NH4, Cs) crystallizes as the second Cs isomer, that is, (exo)2(endo)1, wherein only one CN(t) ligand interacts with the included cation. The distorted framework of NH4 subset Rh4Ru3 reflects the smaller ionic radius of NH4+. The protons of NH4+ were located crystallographically, allowing precise determination of the novel NH4...CN interaction. A competition experiment between calix[4]arene-bis(benzocrown-6) and NH4 subset Rh4Ru3 reveals NH4 subset Rh4Ru3 has a higher affinity for cesium.  相似文献   

12.
Thallium(III) oxide can be dissolved in water in the presence of strongly complexing cyanide ions. Tl(III) is leached from its oxide both by aqueous solutions of hydrogen cyanide and by alkali-metal cyanides. The dominating cyano complex of thallium(III) obtained by dissolution of Tl2O3 in HCN is [Tl(CN)3(aq)] as shown by 205Tl NMR. The Tl(CN)3 species has been selectively extracted into diethyl ether from aqueous solution with the ratio CN-/Tl(III) = 3. When aqueous solutions of the MCN (M = Na+, K+) salts are used to dissolve thallium(III) oxide, the equilibrium in liquid phase is fully shifted to the [Tl(CN)4]- complex. The Tl(CN)3 and Tl(CN)4- species have for the first time been synthesized in the solid state as Tl(CN)3.H2O (1), M[Tl(CN)4] (M = Tl (2) and K (3)), and Na[Tl(CN)4].3H2O (4) salts, and their structures have been determined by single-crystal X-ray diffraction. In the crystal structure of 1, the thallium(III) ion has a trigonal bipyramidal coordination with three cyanide ions in the equatorial plane, while an oxygen atom of the water molecule and a nitrogen atom from a cyanide ligand, attached to a neighboring thallium complex, form a linear O-Tl-N fragment. In the three compounds of the tetracyano-thallium(III) complex, 2-4, the [Tl(CN)4]- unit has a distorted tetrahedral geometry. Along with the acidic leaching (enhanced by Tl(III)-CN- complex formation), an effective reductive dissolution of the thallium(III) oxide can also take place in the Tl2O3-HCN-H2O system yielding thallium(I), while hydrogen cyanide is oxidized to cyanogen. The latter is hydrolyzed in aqueous solution giving rise to a number of products including (CONH2)2, NCO-, and NH4+ detected by 14N NMR. The crystalline compounds, Tl(I)[Tl(III)(CN)4], Tl(I)2C2O4, and (CONH2)2, have been obtained as products of the redox reactions in the system.  相似文献   

13.
Two iodopalladates of the same empirical formula with palladium in different oxidation states were synthesized from aqueous HI solution. Their crystal structures were characterized by single-crystal X-ray analysis, and the effect of hydrostatic pressure on the structural properties has been investigated. Dicesium hexaiodopalladate(IV), Cs2PdI6, crystallizes in a cubic system, space group Fm3m, with a = 11.332(1) A and Z = 4, and is isotypic to K2PtCl6. The second compound, dicesium tetraiodopalladate(II) diiodine, Cs2PdI4.I2, shows tetragonal symmetry with space group I4/mmm, a = 8.987(1) A, c = 9.240(1) A, and Z = 2. The crystal structure can be described in resemblance to the Cs2Au(I)Au(III)Cl6 type. Structural relationships and chemical and structural transformation between both compounds will be discussed. DTA measurements at ambient pressure showed liberation of I2 and decomposition of the compounds. Cs2PdI4.I2 represents an excellent example for studying a solid-state electron-transfer reaction. The redox reaction to Cs2PdI6 can be demonstrated by performing pressure-dependent X-ray studies.  相似文献   

14.
On heating the hydrated complexes 18-Crown[6].M[H(2)PO(4)].xH(2)O (x= 2 for M = K, Rb; x= 1.5 for M = Cs), quantitatively prepared by mechanical mixing of crystalline 18-Crown[6] and M[H(2)PO(4)], to ca. 60 degrees C, water loss takes place, accompanied by the extrusion of the crown ether from the crystalline complex and followed by reconstruction of the inorganic phase M[H(2)PO(4)](M = K, Rb, Cs); the resulting solid mixture reverts to 18-Crown[6].M[H(2)PO(4)].xH(2)O (x= 2 for M = K, Rb; x= 1.5 for M = Cs) upon grinding in air.  相似文献   

15.
The caesium triphosphenide Cs[tBu3SiPPPSitBu3] was accessible from the reaction of CsF with the sodium triphosphenide Na[tBu3SiPPPSitBu3] in tetrahydrofuran at room temperature. In contrast to the preparation of tetrahydrofuran-solvated silanides M[SitBu3] (M = Li, Na, K), our efforts to synthesize the caesium silanide Cs[SitBu3] as a tetrahydrofuran complex failed. When tBu3SiBr was treated with an excess of caesium metal in tetrahydrofuran at room temperature, the caesium enolate Cs[OCH=CH2] and the supersilane tBu3SiH formed rather than the silanide Cs[SitBu3]. X-Ray quality crystals of the enolate Cs[OCH=CH2] (orthorhombic, Pnma) were obtained from tetrahydrofuran at ambient temperature. In contrast to the structures of its homologues M[tBu3SiPPPSitBu3] (M = Na, K), the caesium triphosphenide Cs[tBu3SiPPPSitBu3] features a polymer in the solid state (orthorhombic, Cmcm).  相似文献   

16.
The high-temperature phases of the alkali-metal oxalates M2[C2O4] (M = K, Rb, Cs), and their decomposition products M2[CO3] (M = K, Rb, Cs), were investigated by fast, angle-dispersive X-ray powder diffraction with an image-plate detector, and also by simultaneous differential thermal analysis (DTA)/thermogravimetric analysis (TGA)/mass spectrometry (MS) and differential scanning calorimetry (DSC) techniques. The following phases, in order of decreasing temperature, were observed and crystallographically characterized (an asterisk denotes a previously unknown modification): *alpha-K2[C2O4], *alpha-Rb2[C2O4], *alpha-Cs2[C2O4], alpha-K2[CO3], *alpha-Rb2[CO3], and *alpha-Cs2[CO3] in space group P6(3)/mmc; *beta-Rb2[C2O4], *beta-Cs2[C2O4], *beta-Rb2[CO3], and *beta-Cs2[CO3] in Pnma; gamma-Rb2[C2O4], gamma-Cs[C2O4], gamma-Rb2[CO3], and gamma-Cs2[CO3] in P2(1)/c; and delta-K2[C2O4] and delta-Rb2[C2O4] in Pbam. With respect to the centers of gravity of the oxalate and carbonate anions, respectively, the crystal structures of all known alkali-metal oxalates and carbonates belong to the AlB2 family, and adopt either the AlB2 or the Ni2In arrangement depending on the size of the cation and the temperature. Despite the different sizes and constitutions of the carbonate and oxalate anions, the high-temperature phases of the alkali-metal carbonates M2[CO3] (M = K, Rb, Cs), exhibit the same sequence of basic structures as the corresponding alkali-metal oxalates. The topological aspects and order-disorder phenomena at elevated temperature are discussed.  相似文献   

17.
3-(2-Propenyl)benzothiazolium bromide () provides a direct and simple entry to Pd(ii) complexes with N,S-heterocyclic carbene (NSHC) ligands functionalized with an allyl pendant with hemilabile potential. Addition of salt to Pd(OAc)(2) eliminates HOAc and affords the bis(carbene) complexes cis-[PdBr(2)(NHSC)(2)] (cis-, NSHC = 3-(2-propenyl)benzothiazolin-2-ylidene) and trans-[PdBr(2)(NHSC)(2)] (trans-) along with the monocarbene complexes [PdBr(2)(NSHC)] () and trans-[PdBr(2)(benzothiazole-kappaN)(NSHC)] () as minor side products. Salt-metathesis of cis- with AgO(2)CCF(3) yields the mixed dicarboxylato-bis(carbene) complex cis-[Pd(O(2)CCF(3))(2)(NSHC)(2)] (). Complexes cis-, trans- and were characterized by multinuclear NMR spectroscopies, ESI mass spectrometry and elemental analysis. The molecular structures of complexes cis-, and have been determined by X-ray single crystal diffraction. Complexes cis- and as well as an in situ mixture of Pd(OAc)(2) and salt are active toward Suzuki-Miyaura coupling of aryl bromides and activated aryl chlorides giving good conversions.  相似文献   

18.
在二甲亚砜(DMSO)中, 以MnCl2.2H2O和K3[Cr(Ox)3].3H2O为原料, 合成了离子型配合物[Mn(phen)2(H2O)2]2[Cr(OX)3][HOCH2CH2O].4H2O。晶体结构测定表明, 该晶体属单斜晶系, P2/c空间群。晶体学参数: a=1.0602(3),b=1.3515(3), c=2.1508(3)nm, β=102.57(2)°, V=3.008(1)nm^3, Z=2,Dc=1.49g/cm^3, F(000)=1392。最后的偏差因子R=0.067。测定了化合物的UV-Vis-NIR, IR, XPS, ESR光谱和变温磁化率, 讨论了相应的性质。  相似文献   

19.
The reaction of 2 equiv of the air-stable primary phosphine (ferrocenylmethyl)phosphine (PH2CH2Fc, 1) with [Pd(cod)Cl2] (Fc = ferrocenyl; cod = 1,5-cyclooctadiene) at 298 K gave the phosphanido-bridged Pd(II) tetramer [Pd(PH2CH2Fc)Cl(mu-PHCH2Fc)]4 (2), which shows an unprecedented arrangement of four Pd atoms embedded in an eight-membered Pd4P4 ring. An X-ray diffraction study showed that 2 crystallizes in the triclinic space group P with a = 17.607(7) A, b = 17.944(7) A, c = 18.792(7) A, alpha = 107.120(12) degrees, beta = 96.344(13) degrees, gamma = 117.087(15) degrees . Each molecule contains four palladium atoms in a distorted square-planar coordination formed by one chlorine and three phosphorus atoms. Two of the latter belong to bridging primary phosphanides and the remaining one is contributed by a terminal PH2CH2Fc ligand. The coordination environments of neighboring metal centers adopt an almost perpendicular mutual orientation. The reaction of 2 equiv of 1 with [Pt(cod)Cl2] at 323 K yielded the analogous Pt(II) tetramer of formula [Pt(PH2CH2Fc)Cl(mu-PHCH2Fc)]4 (3), which was fully characterized by multinuclear and dynamic NMR, IR, and elemental analyses. Single-crystal X-ray diffraction on 3 confirmed the tetranuclear arrangement in the solid state, but orientational disorder of the molecule precludes a more detailed discussion of the structure. Low-temperature NMR experiments in CD2Cl2 showed the presence of two slowly interconnecting conformers. Reaction of 1 and [M(cod)Cl2] (M = Pd or Pt) at lower temperatures (273 K for Pd, 295 K for Pt) in dichloromethane allowed the detection in solution of the mononuclear species cis-[M(PH2CH2Fc)2Cl2] (M = Pd, 4; M = Pt, 5) which, upon heating, transformed into the tetramers 2 and 3, respectively. Solid samples of 4 and 5 could be isolated after workup at low temperature and were characterized by conventional spectroscopic methods.  相似文献   

20.
The X-ray structure of Cs(2)[Ni(CN)(4)].H(2)O and the polarized single-crystal UV absorbance spectra of Cs(2)[Ni(CN)(4)].H(2)O and Cs(2)[Pt(CN)(4)].H(2)O are presented. The two complexes are isostructural, with helical arrangements of M(CN)(4)(2)(-) ions in which there is moderate metal-metal electronic perturbation resulting in a spectral red shift from solution in the UV absorbance spectra. In addition, we have modeled the nickel system with a ZINDO calculation of a three-molecule segment of the helix and have found remarkably good agreement with experiment, including excellent reproduction of the red shift. Crystal data are as follows: Cs(2)[Ni(CN)(4)].H(2)O, hexagonal, space group P6(1), a = 9.5260(10) A, c = 19.043(2) A, V = 1496.5(3) A(3), T = 100 K, Z = 6, 4335 observed data, R = 0.016, R(w) = 0.034.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号