New halide-centered discrete Ag(I)(8) cubic clusters containing diselenophosphate ligands, [Ag(8)(X)[Se(2)P(OR)(2)](6)](PF(6)) (X = Cl, Br; R = Et, Pr, (i)Pr): syntheses, structures, and DFT calculations

Six clusters Ag(8)(micro(8)-X)[Se(2)P(OR)(2)](6)(PF(6)) (R = Et, X = Cl, 1a, X = Br, 1b; R = Pr, X = Cl, 2a, X = Br, 2b; R = (i)Pr, X = Cl, 3a, X = Br, 3b) were isolated from the reaction of [Ag(CH(3)CN)(4)](PF(6)), NH(4)[Se(2)P(OR)(2)], and Bu(4)NX in a molar ratio of 4:3:1 in CH(2)X(2). Positive FAB mass spectra show m/z peaks at 2573.2 for 1a, 2617.3 for 1b, 2740.9 for 2a, 2786.9 for 2b, 2742.3 for 3a, and 2787.0 for 3b due to respective molecular cation, (M - PF(6))(+). (31)P NMR spectra of 1a-3b display a singlet at delta 82.3, 81.5, 82.9, 81.7, 76.3, and 75.8 ppm with a set of satellites (J(PSe) = 661, 664, 652, 652, 656, and 656 Hz, respectively). The X-ray structure (1a-2b) consists of a discrete cationic cluster in which eight silver ions are linked by six diselenophosphate ligands and a central micro(8)-Cl or micro(8)-Br ion with a noncoordinating PF(6)(-) anion. The shape of the molecule is a halide-centered distorted Ag(8) cubic cluster. The dsep ligand exhibits a tetrametallic tetraconnective (micro(2), micro(2)) coordination pattern, and each caps on a square face of the cube. Each silver atom of the cube is coordinated by three selenium atoms and the central chloride or bromide ion. Additionally, molecular orbital calculations at the B3LYP level of the density functional theory have been carried out to study the Ag-micro(8)-X (X = Cl, Br) interactions for cluster cations [Ag(8)(micro(8)-X)[Se(2)P(OR)(2)](6)](+). Calculations show very weak bonding interactions exist between micro(8)-X and Ag atoms of the cube.     

Novel chloride-centered discrete CuI8 cubic clusters containing diselenophosphate ligands. Syntheses and structures of [Cu8(mu8-Cl)[Se2P(OR)2](6)](PF6) (R = Et,Pr, iPr)1

Three clusters 1-3, Cu(8)(mu8-Cl)[Se(2)P(OR)(2)](6)(PF(6)) (R= Et, Pr, (i)Pr), were synthesized in high yield from the reaction of [Cu(CH(3)CN)(4)](PF(6)), NH(4)[Se(2)P(OR)(2)], and Bu(4)NCl in a molar ratio of 4:3:1 in diethyl ether. FAB mass spectra show m/z peaks at 2218.10 for 1, 2386.10 for 2, and 2387.34 for 3 which are due to molecular cations, [1-PF(6)]+, [2-PF(6)]+, and [3-PF(6)]+, respectively. (31)P NMR spectra of 1-3 display a singlet at delta 76.48, 76.73, and 69.32 ppm with satellites (J(PSe) = 652, 653, and 648 Hz), respectively. The (77)Se NMR spectra of 1-3 exhibit a doublet peak at -21.7, -16.42, and 2.3 ppm, respectively (J(SeP) = 652 Hz for 1, 653 Hz for 2, and 648 Hz for 3). The X-ray structure (1-3) consists of a discrete cationic cluster in which eight copper ions are linked by six diselenophosphate ligands and a central mu8-Cl ion with a noncoordinating PF(6)(-) anion. The shape of the molecule is a chloride-centered distorted Cu(8) cube in clusters 1 and 2 and a near perfect Cu(8) cube for cluster 3. The dsep ligand exhibits a tetrametallic tetraconnective (mu2, mu2)) coordination pattern, and each occupies a square face of the cube. Each copper atom of the cube is coordinated by three selenium atoms with a strong interaction with the central chloride ion. The observed Cu-Cl distances lie in the range 2.649-2.878 A.     

The inverse sandwich complex [(K(18-crown-6))2Cp][CpFe(CO)2]--unpredictable redox reactions of [CpFe(CO)2]I with the silanides Na[SiRtBu2] (R = Me, tBu) and the isoelectronic phosphanyl borohydride K[PtBu2BH3

The dimeric iron carbonyl [CpFe(CO)(2)](2) and the iodosilanes tBu(2)RSiI were obtained from the reaction of [CpFe(CO)(2)]I with the silanides Na[SiRtBu(2)] (R = Me, tBu) in THF. By the reactions of [CpFe(CO)(2)]I and Na[SiRtBu(2)] (R = Me, tBu) the disilanes tBu(2)RSiSiRtBu(2) (R = Me, tBu) were additionally formed using more than one equivalent of the silanide. In this context it should be noted that reduction of [CpFe(CO)(2)](2) with Na[SitBu(3)] gives the disilanes tBu(3)SiSitBu(3) along with the sodium ferrate [(Na(18-crown-6))(2)Cp][CpFe(CO)(2)]. The potassium analogue [(K(18-crown-6))(2)Cp][CpFe(CO)(2)] (orthorhombic, space group Pmc2(1)), however, could be isolated as a minor product from the reaction of [CpFe(CO)(2)]I with [K(18-crown-6)][PtBu(2)BH(3)]. The reaction of [CpFe(CO)(2)](2) with the potassium benzophenone ketyl radical and subsequent treatment with 18-crown-6 yielded the ferrate [K(18-crown-6)][CpFe(CO)(2)] in THF at room temperature. The crown ether complex [K(18-crown-6)][CpFe(CO)(2)] was analyzed using X-ray crystallography (orthorhombic, space group Pna2(1)) and its thermal behaviour was investigated.     

Two enantiomers of [Cu(3)(mnt)(3)](3-) as ligands to Cu(i) or Ag(i) in building [Cu(6)M(2)(mnt)(6)](4-) complexes (M = Cu or Ag) with the reversal of the reaction by X(-) (X = Cl, Br)

Two enantiomers of [Bu(4)N](3)[Cu(3)(mnt)(3)] () formed by Na(2)(mnt) (mnt = maleonitriledithiolate, [S(2)C(2)(CN)(2)](2-)) and CuCl in a 1 : 1 molar ratio react further with MCl (M = Cu or Ag) involving both the enantiomers of to produce the larger complex, [Bu(4)N](4)[Cu(6)M(2)(mnt)(6)] (M = Cu (2), Ag (3)) from which the capped Cu(+) or Ag(+) ion can readily be removed by Bu(4)NX (X = Cl, Br), reverting or back to . Such reversal does not work with non-coordinating anions like BF(4)(-), ClO(4)(-) and PF(6)(-).     

Novel metalloreagent Cp(CO)2FeP(Se)(OR)2 produced from P-Se bond cleavage in the thermal reaction of [CpFe(CO)2]2 with phosphor-1,1-diselenolates

The reaction of [CpFe(CO)2]2 with NH4Se2P(OR)2 yields a novel reagent Cp(CO)2FeP(Se)(OR)2, which has demonstrated coordination properties at the Se center to form heterometallic clusters as well as reactivity at the Se site toward C-based electrophiles.     

Luminescent homo- and heteropolynuclear platinum(II) chalcogenido aggregates based on [Pt2E2(P empty set N)4] units (E=S,Se)

A series of homodinuclear platinum(II) complexes containing bridging chalcogenido ligands, [Pt(2)(mu-E)(2)(P empty set N)(4)] (P empty set N=dppy, E=S (1), Se (2); P empty set N=tBu-dppy, E=S (3)) (dppy=2-(diphenylphosphino)pyridine, tBu-dppy=4-tert-butyl-2-(diphenylphosphino)pyridine) have been synthesized and characterized. The nucleophilicity of the [Pt(2)E(2)] unit towards a number of d(10) metal ions and complexes has been demonstrated through the successful isolation of a number of novel heteropolynuclear platinum(II)-copper(I), -silver(I), and -gold(I) complexes: [[Pt(2)(mu(3)-E)(2)(dppy)(4)](2)Ag(3)](PF(6))(3) (E=S (4); Se (5)) and [Pt(2)(dppy)(4)(mu(3)-E)(2)M(2)(dppm)]X(2) (E=S, M=Ag, X=BF(4) (6); E=S, M=Cu, X=PF(6) (7); E=S, M=Au, X=PF(6) (8); E=Se, M=Ag, X=PF(6) (9); E=Se, M=Au, X=PF(6) (10)). Some of them display short metal.metal contacts. These complexes have been found to possess interesting luminescence properties. Through systematic comparison studies, the emission origin has been probed.     

Electronic and Geometric Structure of Bimetallic Clusters: Density Functional Calculations on [M(4){Fe(CO)(4)}(4)](4-) (M = Cu, Ag, Au) and [Ag(13){Fe(CO)(4)}(8)](n)(-) (n = 0-5)

The results of all-electron density functional calculations on the bimetallic cluster compounds [M(4){Fe(CO)(4)}(4)](4-) (M = Cu, Ag, Au) and on the corresponding naked species M(4)Fe(4) are reported. The trends within the triad have been investigated. The bare metal clusters exhibit a strong magnetization which is quenched on addition of CO ligands. The bonding in the bare clusters is different for the silver derivative compared to that of copper and gold, resulting in comparatively weaker Ag-Fe and Ag-Ag bonds. This can be rationalized in terms of the different d-sp mixing, which for Cu and Au is larger than for Ag. Relativistic effects act to increase the 4d-5s mixing in Ag and to strengthen the intermetallic bond with Fe. In the carbonylated clusters a charge transfer from the metal M (M = Cu, Ag, or Au) to the Fe(CO)(4) groups occurs so that the atoms M can be considered in a formal +I oxidation state, rationalizing the nearly square-planar geometry of the metal frame. In fact, the local coordination of the M atoms is almost linear, as expected for complexes of M(I). The addition of extra electrons results in a stabilization of the clusters, indicating the electron-deficient nature of these compounds. Similar features have been found for the largest cluster synthesized so far for this class of compounds, [Ag(13){Fe(CO)(4)}(8)](n)(-), (n = 0-5). The nature and localization of the unpaired electron in the tetraanion is also discussed.     

A nonacoordinated bridging selenide in a tricapped trigonal prismatic geometry identified in undecanuclear copper clusters: syntheses, structures, and DFT calculations

Undecanuclear copper clusters, [Cu(11)(micro(9)-Se)(micro(3)-Br)(3)[Se(2)P(OR)(2)](6)] (R = Et, Pr, (i)Pr) (1a-c), were isolated along with closed-shell ion-centered cubes, [Cu(8)(micro(8)-Br)[Se(2)P(OR)(2)](6)] (PF(6)) (2a-c) and [Cu(8)(micro(8)-Se)[Se(2)P(OR)(2)](6)] (3a-c), from the reaction of [Cu(CH(3)CN)(4)](PF(6)), NH(4)[Se(2)P(OR)(2)], and Bu(4)NBr in a molar ratio of 2:3:2 in CH(2)Br(2). The molecular formulations of these clusters were confirmed by elemental analysis, positive FAB mass spectrometry, and multinuclear NMR ((1)H, (31)P, and (77)Se). (77)Se NMR spectra of Cu(11) clusters (1a-c) are of special interest as two inequivalent selenium nuclei of the diselenophosphate (dsep) ligand exhibit different scalar coupling patterns with the adjacent phosphorus nuclei. X-ray analysis of 1c reveals a Cu(11)Se core stabilized by three bromide and six dsep ligands. The central core adopts the geometry of a 3,3,4,4,4-pentacapped trigonal prism with a selenium atom in the center. The coordination geometry for the nonacoordinate selenium atom is tricapped trigonal prismatic. The X-ray structure 2a or 2c consists of a cationic cluster in which eight copper ions are linked by six diselenophosphate ligands with a central micro(8)-Br ion. The shape of the molecule is a bromide-centered distorted Cu(8) cube. Each diselenophosphate ligand occupies square faces of the cube and adopts a tetrametallic tetraconnective coordination pattern. Each copper atom of the cube is coordinated by three selenium atoms with a strong interaction with the central bromide ion. Molecular orbital calculations at the B3LYP level of the density functional theory have been carried out to study the Cu-micro(9)-Se interactions for clusters [Cu(11)(micro(9)-Se)(micro(3)-X)(3)[Se(2)P(OR)(2)](6)] (X = Br, I). Calculations show that the formal bond order of each Cu-micro(9)-Se bond is slightly smaller than half of those calculated for the terminal Cu-micro(2)-Se bonds.     

Structural similarities and differences among mixed-metal clusters containing a single M(PPh3) (M = Cu, Ag or Au) fragment

The heteronuclear metal clusters [H₃MRu₄(CO)₁₂(PPh₃)] and [MFe₃(μ-COMe)(CO)₁₀(PPh₃)] (M = Cu, Ag or Au) have been prepared; the gold-tetraruthenium cluster has a different metal core geometry to that adopted by the copper and silver analogues, whereas all three iron-Group IB mixed-metal clusters have the same geometry.     

Highly luminescent gold(I)-silver(I) and gold(I)-copper(I) chalcogenide clusters

The reactions of [AuClL] with Ag(2)O, where L represents the heterofunctional ligands PPh(2)py and PPh(2)CH(2)CH(2)py, give the trigoldoxonium complexes [O(AuL)(3)]BF(4). Treatment of these compounds with thio- or selenourea affords the triply bridging sulfide or selenide derivatives [E(AuL)(3)]BF(4) (E=S, Se). These trinuclear species react with Ag(OTf) or [Cu(NCMe)(4)]PF(6) to give different results, depending on the phosphine and the metal. The reactions of [E(AuPPh(2)py)(3)]BF(4) with silver or copper salts give [E(AuPPh(2)py)(3)M](2+) (E=O, S, Se; M=Ag, Cu) clusters that are highly luminescent. The silver complexes consist of tetrahedral Au(3)Ag clusters further bonded to another unit through aurophilic interactions, whereas in the copper species two coordination isomers with different metallophilic interactions were found. The first is analogous to the silver complexes and in the second, two [S(AuPPh(2)py)(3)](+) units bridge two copper atoms through one pyridine group in each unit. The reactions of [E(AuPPh(2)CH(2)CH(2)py)(3)]BF(4) with silver and copper salts give complexes with [E(AuPPh(2)CH(2)CH(2)py)(3)M](2+) stoichiometry (E=O, S, Se; M=Ag, Cu) with the metal bonded to the three nitrogen atoms in the absence of AuM interactions. The luminescence of these clusters has been studied by varying the chalcogenide, the heterofunctional ligand, and the metal.     

Reactivity of the heterometallic clusters [HMCo3(CO)12] and [Et4N][MCo3(CO)12] (M = Fe, Ru) toward phosphine selenides, including selenium transfer. Crystal structures of [HRuCo3(CO)7(mu-CO)3(mu-dppy)], [MCo2(mu3-Se)(CO)7(mu-dppy)], and [RuCo2(mu3-Se)(CO)7(mu-dppm)] [dppy = Ph2(2-C5H4N)P, dppm = Ph2PCH2PPh2

The reactivity of [HMCo3(CO)12] and [Et4N][MCo3(CO)12] (M = Fe, Ru) toward phosphine selenides such as Ph3PSe, Ph2P(Se)CH2PPh2, Ph2(2-C5H4N)PSe, Ph2(2-C4H3S)PSe, and Ph2[(2-C5H4N)(2-C4H2S)]PSe has been studied with the aim to obtain new selenido-carbonyl bimetallic clusters. The reactions of the hydrido clusters give two main classes of products: (i) triangular clusters with a mu3-Se capping ligand of the type [MCo2(mu3-Se)(CO)(9-x)L(y)] resulting from the selenium transfer (x = y = 1, 2, with L = monodentate ligand; x = 2, 4, and y = 1, 2, with L = bidentate ligand) (M = Fe, Ru) and (ii) tetranuclear clusters of the type [HMCo3(CO)12xL(y)] obtained by simple substitution of axial, Co-bound carbonyl groups by the deselenized phosphine ligand. The crystal structures of [HRuCo3(CO)7(mu-CO)3(mu-dppy)] (1), [MCo2(mu3-Se)(CO)7(mu-dppy)] (M = Fe (16) or Ru (2)), and [RuCo2(mu3-Se)(CO)7(mu-dppm)] (12) are reported [dppy = Ph2(2-C5H4N)P, dppm = Ph2PCH2PPh2]. Clusters 2, 12, and 16 are the first examples of trinuclear bimetallic selenido clusters substituted by phosphines. Their core consists of metal triangles capped by a mu3-selenium atom with the bidentate ligand bridging two metals in equatorial positions. The core of cluster 1 consists of a RuCo3 tetrahedron, each Co-Co bond being bridged by a carbonyl group and one further bridged by a dppy ligand. The coordination of dppy in a pseudoaxial position causes the migration of the hydride ligand to the Ru(mu-H)Co edge. In contrast to the reactions of the hydrido clusters, those with the anionic clusters [MCo3(CO)12]- do not lead to Se transfer from phosphorus to the cluster but only to CO substitution by the deselenized phosphine.     

Synthesis and characterisation of complexes of Group 13 metal amidinate heterocycles with the CpFe(CO)2 fragment

The first examples of complexes between a 4-membered amidinato-Group 13 metal(III) heterocycle and a transition metal fragment are formed in salt elimination reactions between Na[CpFe(CO)2] and [MX2(amid)], M=Al, Ga or In; X=Cl or Br; amid-=[(RN)2CBut]-; R=Pri or cyclohexyl (Cy). The formed complexes, [CpFe(CO)2M(X)(amid)] (4 examples) have been crystallographically characterised and subject to halide abstraction reactions. In one case, the cationic complex, [CpFe(CO)2Ga(OEt2){(CyN)2CBut}][BArf4], was isolated and crystallographically characterised. A hydrolysis product of this complex, [{CpFe(CO)2Ga[(CyN)2CBut]}2(micro-OH)][BArf4], was also isolated in low yield from this reaction and structurally characterised.     

Preparation and characterization of the argentates: [Ag[P(CF(3))(2)](2)](-), [Ag[(micro-P(CF(3))(2))M(CO)(5)](2)](-) (M = Cr, W), and [Ag[(micro-P(C(6)F(5))(2))W(CO)(5)](2)](-): X-ray crystal structure of [K(18-crown-6)][Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)

The first example of a mononuclear diphosphanidoargentate, bis[bis(trifluoromethyl)phosphanido]argentate, [Ag[P(CF(3))(2)](2)](-), is obtained via the reaction of HP(CF(3))(2) with [Ag(CN)(2)](-) and isolated as its [K(18-crown-6)] salt. When the cyclic phosphane (PCF(3))(4) is reacted with a slight excess of [K(18-crown-6)][Ag[P(CF(3))(2)](2)], selective insertion of one PCF(3) unit into each silver phosphorus bond is observed, which on the basis of NMR spectroscopic evidence suggests the [Ag[P(CF(3))P(CF(3))(2)](2)](-) ion. On treatment of the phosphane complexes [M(CO)(5)PH(CF(3))(2)] (M = Cr, W) with [K(18-crown-6)][Ag(CN)(2)], the analogous trinuclear argentates, [Ag[(micro-P(CF(3))(2))M(CO)(5)](2)](-), are formed. The chromium compound [K(18-crown-6)][Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)] crystallizes in a noncentrosymmetric space group Fdd2 (No. 43), a = 2970.2(6) pm, b = 1584.5(3) pm, c = 1787.0(4), V = 8.410(3) nm(3), Z = 8. The C(2) symmetric anion, [Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)](-), shows a nearly linear arrangement of the P-Ag-P unit. Although the bis(pentafluorophenyl)phosphanido compound [Ag[P(C(6)F(5))(2)](2)](-) has not been obtained so far, the synthesis of its trinuclear counterpart, [K(18-crown-6)][Ag[(micro-P(C(6)F(5))(2))W(CO)(5)](2)], was successful.     

Chemistry of the oxophosphinidene ligand. 2. Reactivity of the anionic complexes [MCp{P(O)R*}(CO)(2)](-) (M = Mo, W; R* = 2,4,6-C(6)H(2)(t)Bu(3)) toward electrophiles based on elements different from carbon

The anionic oxophosphinidene complexes (H-DBU)[MCp{P(O)R*}(CO)(2)] (M = Mo, W; R* = 2,4,6-C(6)H(2)(t)Bu(3); Cp = η(5)-C(5)H(5), DBU = 1,8-diazabicyclo [5.4.0] undec-7-ene) displayed multisite reactivity when faced with different electrophilic reagents. The reactions with the group 14 organochloride compounds ER(4-x)Cl(x) (E = Si, Ge, Sn, Pb) led to either phosphide-like, oxophosphinidene-bridged derivatives [MCp{P(OE')R*}(CO)(2)] (E' = SiMe(3), SiPh(3), GePh(3), GeMe(2)Cl) or to terminal oxophosphinidene complexes [MCp{P(O)R*}(CO)(2)(E')] (E' = SnPh(3), SnPh(2)Cl, PbPh(3); Mo-Pb = 2.8845(4) ? for the MoPb compound). A particular situation was found in the reaction with SnMe(3)Cl, this giving a product existing in both tautomeric forms, with the phosphide-like complex [MCp{P(OSnMe(3))R*}(CO)(2)] prevailing at room temperature and the tautomer [MCp{P(O)R*}(CO)(2)(SnMe(3))] being the unique species present below 203 K in dichloromethane solution. The title anions also showed a multisite behavior when reacting with transition-metal based electrophiles. Thus, the reactions with the complexes [M'Cp(2)Cl(2)] (M' = Ti, Zr) gave phosphide-like derivatives [MCp{P(OM')R*}(CO)(2)] (M = Mo, M' = TiCp(2)Cl, ZrCp(2)Cl; M = W, M' = ZrCp(2)Cl), displaying a bridging κ(1),κ(1)-P,O- oxophosphinidene ligand connecting MCp(CO)(2) and M'Cp(2)Cl metal fragments (W-P = 2.233(1) ?, O-Zr = 2.016(4) ? for the WZr compound]. In contrast, the reactions with the complex [AuCl{P(p-tol)(3)}] gave the metal-metal bonded derivatives trans-[MCp{P(O)R*}(CO)(2){AuP(p-tol)(3)}] (M = Mo, W; Mo-Au = 2.7071(7) ?). From all the above results it was concluded that the terminal oxophosphinidene complexes are preferentially formed under conditions of orbital control, while charge-controlled reactions tend to give derivatives with the electrophilic fragment bound to the oxygen atom of the oxophosphinidene ligand (phosphide-like, oxophosphinidene-bridged derivatives).     

Syntheses, solid-state structures, and solution studies by VT 31P NMR of [Zn[Se2P(OEt)2]2] infinity and [Zn2[Se2P(OiPr)2]4

Complexes [Zn[Se(2)P(OEt)(2)](2)]( infinity ) (1) and [Zn(2)[Se(2)P(O(i)Pr)(2)](4)] (2) are prepared from the reaction of Zn(ClO(4))(2).6H(2)O and (NH(4))[Se(2)P(OR)(2)] (R = Et and (i)Pr) in a molar ratio of 1:2 in deoxygenated water at room temperature. Positive FAB mass spectra show m/z peaks at 968.8 (Zn(2)L(3)(+)) and 344.8 (ZnL(+)) for 1 and m/z at 1052.8 (Zn(2)L(3)(+)) for 2. (1)H NMR spectra exhibit chemical shifts at delta 1.43 and 4.23 ppm for 1 and 1.41 and 4.87 ppm for 2 due to Et and (i)Pr group of dsep ligands. While the solid-state structure of compound 1 is a one-dimensional polymer via symmetrically bridging dsep ligands, complex 2 in the crystalline state exists as a dimer. In both 1 and 2, zinc atoms are connected by two bridging dsep ligands with an additional chelating ligand at each zinc atom. The dsep ligands exhibit bimetallic biconnective (micro(2), eta(2)) and monometallic biconnective (eta(2)) coordination patterns. Thus, each zinc atom is coordinated by four selenium atoms from two bridging and one chelating dsep ligands and the geometry around zinc is distorted tetrahedral. The Zn-Se distances range between 2.422 and 2.524 A. From variable-temperature (31)P NMR studies it has been found that monomer and dimer of the complex are in equilibrium in solution via exchange of bridging and chelating ligands. However, at temperature above 40 degrees C the complex exists as a monomer and shows a very sharp peak while with lowering of the temperature the percentage of dimer increases gradually at the expense of monomer. Below -90 degrees C the complex exists as a dimer and two peaks are observed with equal intensities which are due to bridging and chelating ligands. (77)Se NMR spectra of both complexes at -30 degrees C exhibit three doublets due to the presence of monomer and dimer in solution.     

Reactivity of Ph2P(Se)CH2C6H4CH2P(Se)Ph2 with [M3(CO)12] (M=Ru or Fe). Synthesis and characterization of the new carbene cluster [Ru3(mu3-Se)(mu3-H)(mu2-PPh2)(CO)6(mu2-CHC6H4CH2PPh2)

The reactions of [M3(CO)12] (M=Ru or Fe) with 1,2 bis[(diphenylphosphino)methyl]benzene diselenide (dpmbSe2) in hot toluene afford a variety of phosphine-substituted selenido carbonyl clusters. They belong to the following three families: (i) 50-electron clusters with a M3Se2 core (2, 3, 5-7), (ii) 48-electron clusters with a M3Se core (1, 8), (iii) 34-electron clusters with a M2Se2 core (4). All these species derive from the P=Se bond cleavage. Cluster 1, which contains a hydrido, a phosphido, and a carbene ligand, is produced by multiple fragmentation of the diphosphine. This fragmentation appears related to the presence of the selenido ligand on the cluster, as the reaction of [Ru3(CO)12] with dpmb (not selenized) produces only carbonyl substitution by the phosphine to give [Ru3(CO)10(mu-dpmb)] (9). All the clusters synthesized have been characterized by spectroscopic techniques, and in some cases fluxional behavior has been detected in solution by NMR analysis. The structures of 1, 2, and 7-9 have been determined by X-ray diffraction methods.     

Tetraphosphinitoresorcinarene complexes: dynamic clusters with silver(I) and copper(I) halides

Silver(I) and copper(I) halide derivatives of several tetrakis(diphenylphosphinito)resorcinarene ligands are reported. The complexes [resorcinarene(O(2)CR)(4)(OPPh(2))(4)(M(5)X(5))], with resorcinarene = (PhCH(2)CH(2)CHC(6)H(2))(4), R = C(6)H(11), 4-C(6)H(4)Me, C(4)H(3)S, OCH(2)CCH, or OCH(2)Ph, M = Ag, X = Cl, Br, or I, M = Cu, and X = Cl or I, contain a crownlike [P(4)M(5)X(5)] metal halide cluster. These crown clusters were found to be dynamic in solution, as studied by variable-temperature NMR, and easily fragment to give the corresponding complexes containing [P(4)M(4)X(5)](-) and [P(4)M(2)(micro-X)](+) units. Reaction of pentasilver crown clusters with triflic acid gave the corresponding disilver complexes [resorcinarene(O(2)CR)(4)(OPPh(2))(4)]Ag(2)(micro-Cl)]]CF(3)SO(3). Thus, these resorcinarene-based ligands act as a platform for the easy and reversible assembly of copper(I) and silver(I) clusters with novel structures.     

Synthesis, Structure, and Reactivities of [eta(2)-P(7)M(CO)(4)](3)(-), [eta(2)-HP(7)M(CO)(4)](2)(-), and [eta(2)-RP(7)M(CO)(4)](2)(-) Zintl Ion Complexes Where M = Mo, W

Ethylenediamine (en) solutions of [eta(4)-P(7)M(CO)(3)](3)(-) ions [M = W (1a), Mo (1b)] react under one atmosphere of CO to form microcrystalline yellow powders of [eta(2)-P(7)M(CO)(4)](3)(-) complexes [M = W (4a), Mo (4b)]. Compounds 4 are unstable, losing CO to re-form 1, but are highly nucleophilic and basic. They are protonated with methanol in en solvent giving [eta(2)-HP(7)M(CO)(4)](2)(-) ions (5) and are alkylated with R(4)N(+) salts in en solutions to give [eta(2)-RP(7)M(CO)(4)](2)(-) complexes (6) in good yields (R = alkyl). Compounds 5 and 6 can also be prepared by carbonylations of the [eta(4)-HP(7)M(CO)(3)](2)(-) (3) and [eta(4)-RP(7)M(CO)(3)](2)(-) (2) precursors, respectively. The carbonylations of 1-3 to form 4-6 require a change from eta(4)- to eta(2)-coordination of the P(7) cages in order to maintain 18-electron configurations at the metal centers. Comparative protonation/deprotonation studies show 4 to be more basic than 1. The compounds were characterized by IR and (1)H, (13)C, and (31)P NMR spectroscopic studies and microanalysis where appropriate. The [K(2,2,2-crypt)](+) salts of 5 were characterized by single crystal X-ray diffraction. For 5, the M-P bonds are very long (2.71(1) ?, average). The P(7)(3)(-) cages of 5 are not displaced by dppe. The P(7) cages in 4-6 have nortricyclane-like structures in contrast to the norbornadiene-type geometries observed for 1-3. (31)P NMR spectroscopic studies for 5-6 show C(1) symmetry in solution (seven inequivalent phosphorus nuclei), consistent with the structural studies for 5, and C(s)() symmetry for 4 (five phosphorus nuclei in a 2:2:1:1:1 ratio). Crystallographic data for [K(2,2,2-crypt)](2)[eta(2)-HP(7)W(CO)(4)].en: monoclinic, space group C2/c, a = 23.067(20) ?, b = 12.6931(13) ?, c = 21.433(2) ?, beta = 90.758(7) degrees, V = 6274.9(10) ?(3), Z = 4, R(F) = 0.0573, R(w)(F(2)) = 0.1409. For [K(2,2,2-crypt)](2)[eta(2)-HP(7)Mo(CO)(4)].en: monoclinic, space group C2/c, a = 22.848(2) ?, b = 12.528(2) ?, c = 21.460(2) ?, beta = 91.412(12) degrees, V = 6140.9(12) ?(3), Z = 4, R(F) = 0.0681, R(w)(F(2)) = 0.1399.     

Coordination Chemistry of 2,2'-Dipyridyl Diselenide: X-ray Crystal Structures of PySeSePy, [Zn(PySeSePy)Cl(2)], [(PySeSePy)Hg(C(6)F(5))(2)], [Mo(SePy)(2)(CO)(3)], [W(SePy)(2)(CO)(3)], and [Fe(SePy)(2)(CO)(2)] (PySeSePy = C(5)H(4)NSeSeC(5)H(4)N; SePy = [C(5)H(4)N(2-Se)-N,Se])

The coordination chemistry of 2,2'-dipyridyl diselenide (PySeSePy) (2) (C(10)H(8)N(2)Se(2)) has been investigated and its crystal structure has been determined (monoclinic, P2(1)/c, a = 10.129(2) ?, b = 5.7332(12) ?, c = 19.173(3) ?, beta = 101.493(8) degrees, Z = 4). In metal complexes the ligand was found to coordinate in three different modes, as also confirmed by X-ray structure determination. N,N'-coordination was found in the zinc complex [Zn(PySeSePy)Cl(2)] (3) (C(10)H(8)Cl(2)N(2)Se(2)Zn, triclinic, P&onemacr;, a = 7.9430(10) ?, b = 8.147(2) ?, c = 11.999(2) ?, alpha = 93.685(10) degrees, beta = 107.763(10) degrees, gamma = 115.440(10) degrees, Z = 2) and Se,Se'-coordination in the adduct of the ligand with bis(pentafluorophenyl)mercury(II) [PySeSePyHg(C(6)F(5))(2)] (5) (C(10)H(8)F(10)HgN(2)Se(2), monoclinic, P2(1)/n, a = 7.7325(10) ?, b = 5.9974(14) ?, c = 25.573, beta = 98.037(10) degrees, Z = 2), which however displays only weak interactions between selenium and mercury. The reaction of the ligand with norbornadiene carbonyl complexes of molybdenum and tungsten leads to reductive cleavage of the selenium-selenium bond with oxidation of the metal center and concomitant addition of the resulting selenolate to the metal carbonyl fragment. Thus the 7-coordinate complexes [Mo(SePy)(2)(CO)(3)] (6) (C(13)H(8)MoN(2)O(3)Se(2), monoclinic, P2(1)/n, a = 9.319(3) ?, b = 12.886(5) ?, c = 13.231(6) ?, beta = 109.23(3) degrees, Z = 4) and [W(SePy)(2)(CO)(3)] (7) (C(13)H(8)N(2)O(3)Se(2)W, monoclinic, P2(1)/n, a = 9.303(2) ?, b = 12.853(2) ?, c = 13.232(2) ?, beta = 109.270(10) degrees, Z = 4) were obtained. The same N,Se-coordination pattern emerges from the reaction of [Fe(2)(CO)(9)] with (2) leading to [Fe(SePy)(2)(CO)(2)] (8) (C(12)H(8)FeN(2)O(2)Se(2), monoclinic, P&onemacr;, a = 8.6691(14) ?, b = 12.443(2) ?, c = 14.085(2) ?, alpha = 105.811(10) degrees, beta = 107.533(8) degrees, gamma = 92.075(10) degrees, Z = 4).     

A Comparative Study of Two New Structure Types. Synthesis and Structural and Electronic Characterization of K(RE)P(2)Se(6) (RE = Y, La, Ce, Pr, Gd)

Two polytypes of potassium rare-earth-metal hexaselenodiphosphates(IV), K(RE)P(2)Se(6) (RE = Y, La, Ce, Pr, Gd), have been synthesized from the stoichiometric reaction of RE, P, Se, and K(2)Se(4) at 750 degrees C. Both single-crystal and powder X-ray diffraction analyses showed that the structures of these polytypes vary with the size of the rare earth metals. For the smaller rare-earth metals, Y and Gd, K(RE)P(2)Se(6) crystallized in the orthorhombic space group P2(1)2(1)2(1). The yttrium compound was studied by single-crystal X-ray diffraction with the cell parameters a = 6.7366(5) ?, b = 7.4286(6) ?, c = 21.603(2) ?, and Z = 4. This structure type comprises a layered, square network of yttrium atoms that are bound to four distinct [P(2)Se(6)](4)(-) units through selenium bonding. Each [P(2)Se(6)](4)(-) unit possesses a Se atom that is not bound to any Y atom but is pointing out into the interlayer spacing, into an environment of potassium cations. For larger rare-earth metals, La, Ce, and Pr, K(RE)P(2)Se(6) crystallized in a second, monoclinic polytype, the structure of which has been published. Both of these two different polytypes can be related to each other and several other isoelectronic chalcophosphate structures based on a Parthé valence electron concentration analysis. These structures include Ag(4)P(2)S(6), K(2)FeP(2)S(6), and the hexagonal M(II)PS(3) structure types. The magnetic susceptibilities of the title compounds have been studied, and the behavior can been explained based on a simple set of unpaired f-electrons. The diffuse reflectance spectroscopy also showed that these yellow plates are moderately wide band gap ( approximately 2.75 eV) semiconductors.