Photochemical reaction channels of OCS with Cl2, ICl, or IBr isolated together in an argon matrix: isolation of syn-iodocarbonylsulfenyl bromide

The photolytically induced reactions of a dihalogen XY (= Cl2, ICl, or IBr) with OCS isolated together in an Ar matrix at about 15 K lead to different photoproducts depending on the natures of X and Y. In addition to the known species ClCO*, OCCl2, syn-ClC(O)SCl, syn-ClC(O)SSCl, IC(O)Cl, IC(O)Br, and syn-BrC(O)SBr, syn-iodocarbonylsulfenyl bromide, syn-IC(O)SBr, has thus been identified for the first time as a photoproduct of the reactions involving IBr. The first product to be formed in the reactions with Cl2 or ICl is the ClCO* radical which reacts subsequently with halogen or sulfur atoms or other matrix guests to give the corresponding carbonyl dihalide (OCCl2 and IC(O)Cl), syn-ClC(O)SCl or syn-ClC(O)SSCl. The analogous reaction with IBr affords syn-BrC(O)SBr, IC(O)Br, and syn-IC(O)SBr. The changes have been followed, the products characterized experimentally by IR measurements, and the spectra analyzed in the light of the results of appropriate theoretical calculations.     

Ruthenium(II)-Phthalocyaninate(1–): Darstellung und Eigenschaften von (Halogeno)(carbonyl)phthalocyaninato(1–)ruthenium(II)

Ruthenium(II)-Phthalocyaninates(1–): Synthesis and Properties of (Halo)(carbonyl)phthalocyaninato(1–)ruthenium(II) Brown-violet (halo)(carbonyl)phthalocyaninato(1–)ruthenium(II), [Ru(X)(CO)Pc^?] (X = Cl, Br) is prepared by oxidation of [Ru(X)(CO)Pc^2?]^? with the corresponding halogen or dibenzoylperoxide. The eff. magnetic moment μ_eff = 1.74 (X = Cl), 1.68 μ_B (Br) confirms the presence of a low-spin Ru^II complex of the Pc^? radical. Accordingly, only the first ring oxidation at ～0.64 V and the first ring reduction at ～ ?1.19 V is observed in the cyclovoltammogram of [Ru(X)(CO)Pc^2?]^?. The UV-VIS-NIR spectra characterizing a monomeric Pc^? radical with intense π-π* transitions at 14500, 19800, 25100 and 33900 cm^?1 are compared with those of [Ru(Cl)₂Pc^?] and of monomeric as well as dimeric [Zn(Cl)Pc^?]. The IR and resonance Raman(RR) spectra are characteristic for a Pc^? radical, too. Diagnostic in-plane vibrations of the Pc^? ligand are in the IR spectrum at 1071, 1359, 1445 cm^?1 and in the RR spectrum (λ₀ = 488.0 nm) at 567, 1597 cm^?1. v(C? O) at 1950 cm^?1 and v(Ru? X) at 260 (X = Cl) resp. 184 cm^?1 (X = Br) are observed only in the IR spectrum.     

Formation of new halogenothiocarbonylsulfenyl halides, XC(S)SY, through photochemical matrix reactions starting from CS2 and a dihalogen molecule XY (XY=Cl2, Br2, or BrCl)

Isolation of a dihalogen molecule XY (XY=Cl2, Br2, or BrCl) with CS2 in a solid Ar matrix at about 15 K leads, by broad-band UV-vis photolysis (200相似文献   

Organometallated Halonium Salts of the Type [{Cp(CO)2Fe}2X]SbY6 (X = Cl,Br, I; Y = F,Cl)

The reaction of CpFe(CO)₂X (X = Cl, Br, I) with SbY₅ (Y = F, Cl) in toluene leads to the cationic, halogen‐bridged compounds [{Cp(CO)₂Fe}₂X]SbY₆ ( 1 – 6 ). The halide of CpFe(CO)₂X is eliminated by the Lewis acid SbY₅, and the fragment “CpFe(CO)₂⁺” reacts with further CpFe(CO)₂X to form the halogen bridge between both the organometallic substituents. The exclusive formation of the counter anion SbY₆^– is caused by the oxidizing action of the antimony pentahalides, by which SbY₃ and the interhalogens XY are always obtained. The compounds have been characterized by their NMR‐, IR‐ and Mass spectra, the compounds 1 – 3 and 6 additionally by single crystal structure analyses. They show decreasing bond angles Fe–X–Fe following the range Cl → Br → I and the VSEPR concept; the two CpFe(CO)₂ groups are staggered with the dihedral angle Cp(centre)–Fe–Fe–Cp(centre) of about 160°.     

Lead rare-earth oxyhalides: syntheses and characterization of Pb6LaO7X (X = Cl, Br)

Yellowish elongated crystals of the two new compounds Pb6LaO7Br (1) and Pb6LaO7Cl (2) have been obtained by the method of solid-state reactions. Both structures can be described in the terms of oxo-centered tetrahedra. The structures of 1 and 2 consist of [O7Pb6La]+ chains that are built from oxocentered OA4 (A = Pb, La) tetrahedra. The halogen ions connect the chains through weak Pb-X bonds. An arrangement of eight OA4 tetrahedra that all share the same central La atom forms a [O8Pb10La3]13+ cluster. The clusters are linked into chains, and additional OPb4 tetrahedra are attached to the chains. Incorporation of Cl atoms instead of Br atoms into the structure causes a lowering of the symmetry from Cmcm to C2/m.     

Dichroic, dinuclear mu2-(eta2-NO)-nitrosoaniline-bridged complexes of rhenium of the type [[(CO)3Re(mu-X)]2ONC6H4NR2] (X = Cl, Br, I; R = Me, Et)

A series of unusual dinuclear mu2-(eta2-NO)-nitrosoaniline-bridged complexes [[(CO)3Re(mu-X)]2ONC6H4NR2] (X = Cl, Br, I; R = Me, Et) with dichroic properties have been synthesised by reaction of pentacarbonylhalogenorhenium(I) [(CO)5ReX] (X = Cl, Br, I) with the corresponding nitrosoaniline derivatives R2NC6H4NO (R = Me, Et). The deeply coloured solutions in CH2Cl2 show broad UV/Vis absorptions from 595 to 620 nm depending on the halogen bridges and N substituents. Single crystals of all six compounds exhibit a pronounced linear dichroism. The molecular structures have been determined by single-crystal X-ray analyses. All the compounds contain two face-shared octahedra, with two halogens and one NO ligand as bridges. The NO ligand coordinates in a nonsymmetrical eta2-like fashion with N or O coordination to each Re centre. Therefore, the C-nitroso group and the planar NC2 moiety of NR2 both lie almost exactly within the symmetry plane of the dinuclear complexes. These complexes belong to the novel and simple class of neutral dinuclear C-nitroso complexes that include the rare, non-assisted mu2-(eta2-NO) ligand function and have only single halogen atoms in bridging positions.     

An alternative synthesis method for [Os(NN)(CO)(2)X(2)] complexes (NN = 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine; X = Cl, Br, I). Electrochemical and photochemical properties and behavior

A novel synthesis method is introduced for the preparation of [Os(NN)(CO)(2)X(2)] complexes (X = Cl, Br, I, and NN = 2,2'-bipyridine (bpy) or 4,4'-dimethyl-2,2'-bipyridine (dmbpy)). In the first step of this two-step synthesis, OsCl(3) is reduced in the presence of a sacrificial metal surface in an alcohol solution. The reduction reaction produces a mixture of trinuclear mixed metal complexes, which after the addition of bpy or dmbpy produce a trans(Cl)-[Os(NN)(CO)(2)Cl(2)] complex with a good 60-70% yield. The halide exchange of [Os(bpy)(CO)(2)Cl(2)] has been performed in a concentrated halidic acid (HI or HBr) solution in an autoclave, producing 30-50% of the corresponding complex. All of the synthesized trans(X)-[Os(bpy)(CO)(2)X(2)] (X = Cl, Br, I) complexes displayed a similar basic electrochemical behavior to that found in the ruthenium analog trans(Cl)-[Ru(bpy)(CO)(2)Cl(2)] studied previously, including the formation of an electroactive polymer [Os(bpy)(CO)(2)](n) during the two-electron electrochemical reduction. The absorption and emission properties of the osmium complexes were also studied. Compared to the ruthenium analogues, these osmium complexes display pronounced photoluminescence properties. The DFT calculations were made in order to determine the HOMO-LUMO gaps and to analyze the contribution of the individual osmium d-orbitals and halogen p-orbitals to the frontier orbitals of the molecules. The electrochemical and photochemical induced substitution reactions of carbonyl with the solvent molecule are also discussed.     

A unique case of oxidative addition of interhalogens IX (X=Cl, Br) to organodiselone ligands: nature of the chemical bonding in asymmetric I-Se-X polarised hypervalent systems

The reactivity of the imidazoline-2-selone derivatives 1,1'-methylenebis(3-methyl-4-imidazoline-2-selone) (D1) and 1,2-ethylenebis(3-methyl-4-imidazoline-2-selone) (D2) towards the interhalogens IBr and ICl has been investigated in the solid state with the aim of synthesising "T-shaped" hypervalent chalcogen compounds featuring the extremely rare linear asymmetric I-E-X moieties (E=S, Se; X=Br, Cl). X-ray diffraction analysis and FT-Raman measurements provided a clear indication of the presence in the compounds obtained of discrete molecular adducts containing I-Se-Br and I-Se-Cl hypervalent moieties following a unique oxidative addition of interhalogens IX (X=Cl, Br) to the organoselone ligands. In all asymmetric hypervalent systems isolated, a strong polarisation was observed, with longer bond lengths at the selenium atom involving the most electronegative halogen. A topological electron density analysis on model compounds based on the quantum theory of atoms-in-molecules (QTAIM) and electron localisation function (ELF) established the three-centre-four-electron (3c-4e) nature of the bonding in these very polarised selenium hypervalent systems and new criteria were suggested to define and ascertain the hypervalency of the selenium atoms in these and related halogen and interhalogen adducts.     

Stereoelectronic and inductive effects on 1H and 13C NMR chemical shifts of some cis-1,3-disubstituted cyclohexanes

This work presents the substituent effects on the 1H and 13C NMR chemical shifts in the cis-isomer of 3-Y-cyclohexanols (Y = Cl, Br, I, CH3, N(CH3)2 and OCH3) and 3-Y-1-methoxycyclohexanes (Y = F, Cl, Br, I, CH3, N(CH3)2 and OCH3). It was observed that the H-3 chemical shift, due to the substituent alpha-effect, increases with the increase of substituent electronegativity when Y is from the second row of the periodic table of elements, (CH3 *sigma(C3--H3a) interaction energy. This interaction energy, for the halogenated compounds, decreases with an increase in size of the halogen, and this is a possible reason for the largest measured chemical shift for H-3 of the iodo-derivatives. The beta-effect of the analyzed compounds showed that the chemical shift of hydrogens at C-2 and C-4 increases with the decrease of n(Y) --> *sigma(C2-C3) and n(Y) --> *sigma(C3-C4) interaction energies, respectively, showing a behavior similar to H-3. The alpha-effect on 13C chemical shifts correlates well with substituent electronegativity, while the beta-effect is inversely related to electronegativity in halogenated compounds. NBO analysis indicated that the substituent inductive effect is the predominant effect on 13C NMR chemical shift changes for the alpha-carbon. It was also observed that C-2 and C-4 chemical shifts for compounds with N(CH3)2, OCH3 and F are more shielded in comparison to the compounds having a halogen, most probably because of the larger interaction of the lone pair of more electronegative atoms (n(N) > n(O) > n(F)) with *sigma(C2-C3), *sigma(C3-C4) and *sigma(C3-H3a) in comparison with the same type of interaction with the lone pair of the other halogens.     

Electronic Structure and Properties of Trihalogen Cations X(3)(+) and XY(2)(+) (X, Y = F, Cl, Br, I)

Electronic structures, charge distributions, geometries, valence force constants, and vibrational frequencies of the homoatomic clusters F(3)(+), Cl(3)(+), Br(3)(+), and I(3)(+) and of the heteroatomic clusters ClF(2)(+), BrF(2)(+), IF(2)(+), BrCl(2)(+), ICl(2)(+), and IBr(2)(+) were determined. The self-consistent field approach extended by MP2-correlation energy or density-functional corrections was applied using various basis sets. It was found that d- and f-type polarization functions play a crucial role as in some other halogen compounds. The MP2 approach yields the most satisfactory results. The effect of the crystalline environment surrounding the Cl(3)(+), Br(3)(+), and I(3)(+) species is successfully simulated by a Madelung potential. Frequencies calculated in the crystal field are in reasonable agreement with the more reliable ones among the experimental results. Coupling force constants were determined. They are not consistent with some empirical rules. Bonding and charge distributions of the formally mixed-valence systems X(+)Y(2)(0) are discussed. X(+) behaves like a divalent chalcogen with high electronegativity. Each of the X(+)-Y bonds in XY(2)(+) is very similar to the bond in X-Y. We predict the experimentally unknown F(3)(+) to be stable in vacuum but not in the solid state. Structures and frequencies of XY(2)(+) species, which are as yet unknown, are also predicted.     

Tuning of spin density wave strengths in quasi-one-dimensional mixed-halogen-bridged nickel(III) complexes with strong electron correlation, [Ni(III)(chxn)(2)Cl(1-x)Br(x)](NO(3))(2)

This communication describes the syntheses of the quasi-one-dimensional mixed-halogen-bridged Ni(III) complexes with strong electron correlation [Ni(chxn)(2)Cl(1-x)Br(x)](NO(3))(2) and the tuning of the spin density wave strengths of these compounds. If the Cl 3p and Br 4p make one band in the compounds, we should observe a single peak in the electronic spectra. As a result, we should observe the single peak from 1.45 to 2.00 eV depending on the mixing ratios of Cl and Br ions. Therefore, the Cl 3p and Br 4p make one band. Then, we have succeeded in tuning the spin density wave strengths of the Ni(III) complexes with the strong electron correlation by mixing the bridging halogen ions successively.     

Haloacyl complexes of boron, [(CF3)3BC(O)Hal]- (Hal=F, Cl, Br, I)

The haloacyltris(trifluoromethyl)borate anions [(CF3)3BC(O)Hal]- (Hal=F, Cl, Br, I) have been synthesized by reacting (CF3)3BCO with either MHal (M=K, Cs; Hal=F) in SO2 or MHal (M=[nBu4N]+, [Et4N]+, [Ph4P]+; Hal=Cl, Br, I) in dichloromethane. Metathesis reactions of the fluoroacyl complex with Me3SiHal (Hal=Cl, Br, I) led to the formation of its higher homologues. The thermal stabilities of the haloacyltris(trifluoromethyl)borates decrease from the fluorine to the iodine derivative. The chemical reactivities decrease in the same order as demonstrated by a series of selected reactions. The new [(CF3)3BC(O)Hal]- (Hal=F, Cl, Br) salts are used as starting materials in the syntheses of novel compounds that contain the (CF3)3B-C fragment. All borate anions [(CF3)3BC(O)Hal]- (Hal=F, Cl, Br, I) have been characterized by multinuclear NMR spectroscopy (11B, 13C, 17O, 19F) and vibrational spectroscopy. [PPh4][(CF3)3BC(O)Br] crystallizes in the monoclinic space group P2/c (no. 13) and the bond parameters are compared with those of (CF3)3BCO and K[(CF3)3BC(O)F]. The interpretation of the spectroscopic and structural data are supported by DFT calculations [B3LYP/6-311+G(d)].     

Phosphinsubstituierte chelatliganden I. Mangan- und rheniumcarbonyl-komplexe mit phosphino-(thio)formamid- und -dithioformiat-liganden

A series of new tetracarbonyl and tricarbonyl complexes of manganese and rhenium with heteroallylic phosphine chelate ligands L  [XC(Y)PPh₂]^? and HXC-(Y)PPh₂ (X, Y  NR, O, S) were prepared by reaction of the appropriate metal carbonyl halides with the free ligands or their silyl intermediates. The silyl method yields both cis-(CO)₄ML and fac-(CO)₃M(X)L (X  Cl, Br) complexes by controlled addition of water. Analytical, spectroscopic and crystallographic data of the ambidentate thioformamide ligands result in a P,S-coordination in all complexes. The ¹³C NMR spectra of several selected compounds were recorded and reveal some unexpected features.     

The matrix-isolated molecular complexes CO/XF (X=Cl,Br,I) and the molecular structure of FC(O)Br

FC(O)Br has been synthesized, and its IR spectrum in the gas phase and isolated in an Ar matrix, as well as, its Raman spectrum in the solid state at -196 degrees C has been analyzed. Its molecular structure has been determined and its UV has been measured. FC(O)Br and FC(O)Cl has been photodissociated in an argon matrix at 17 K with a 193 nm laser. The photolysis produces CO and XF which recombine to form CO/XF complexes. The formation of complexes are followed by the shift of the normal vibration modes with respect to CO and XF isolated in argon matrix. In the case of FC(O)Br, three isomers are identified, OC...BrF, OC...FBr, and CO...BrF, whereas for FC(O)Cl only one isomer is observed, OC...ClF. High level quantum chemical calculations are used to help the assignment of the different isomers.     

Reactions of the Dirhenium(II) Complexes Re(2)X(4)(dppm)(2) (X = Cl, Br; dppm = Ph(2)PCH(2)PPh(2)) with Isocyanides. 10.(1) Synthesis and Characterization of the Complex [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(2)(CNXyl)]O(3)SCF(3) and Several Isomeric Forms of [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)]Y (Y = PF(6), O(3)SCF(3))

The reactions of the unsymmetrical, coordinatively unsaturated dirhenium(II) complexes [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)]Y (XylNC = 2,6-dimethylphenyl isocyanide; Y = O(3)SCF(3) (3a), PF(6) (3b)) with XylNC afford at least three isomeric forms of the complex cation [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)](+). Two forms have very similar bis(&mgr;-halo)-bridged edge-sharing bioctahedral structures of the type [(CO)BrRe(&mgr;-Br)(2)(&mgr;-dppm)(2)Re(CNXyl)(2)]Y (Y = O(3)SCF(3) (4a/4a'), PF(6) (4b/4b')), while the third is an open bioctahedron [(XylNC)(2)BrRe(&mgr;-dppm)(2)ReBr(2)(CO)]Y (Y = O(3)SCF(3) (5a), PF(6) (5b)). While the analogous chloro complex cation [Re(2)Cl(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)](+) was previously shown to exist in three isomeric forms, only one of these has been found to be structurally similar to the bromo complexes (i.e. the isomer analogous to 5a and 5b). The reaction of 3a with CO gives the salt [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(2)(CNXyl)]O(3)SCF(3) (7), in which the edge-sharing bioctahedral cation [(XylNC)BrRe(&mgr;-Br)(&mgr;-CO)(&mgr;-dppm)(2)ReBr(CO)](+) has an all-cis arrangement of pi-acceptor ligands. The Re-Re distances in the structures of 4b', 5a, and 7 are 3.0456(8), 2.3792(7), and 2.5853(13) ?, respectively, and accord with formal Re-Re bond orders of 1, 3, and 2, respectively. Crystal data for [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)](PF(6))(0.78)(ReO(4))(0.22).CH(2)Cl(2) (4b') at 295 K: monoclinic space group P2(1)/n (No. 14) with a = 19.845(4) ?, b = 16.945(5) ?, c = 21.759(3) ?, beta = 105.856(13) degrees, V = 7038(5) ?(3), and Z = 4. The structure was refined to R = 0.060 (R(w) = 0.145) for 14 245 data (F(o)(2) > 2sigma(F(o)(2))). Crystal data for [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)]O(3)SCF(3).C(6)H(6) (5a) at 173 K: monoclinic space group P2(1)/n (No. 14) with a = 14.785(3) ?, b = 15.289(4) ?, c = 32.067(5) ?, beta = 100.87(2) degrees, V=7118(5) ?(3), and Z = 4. The structure was refined to R = 0.046 (R(w) = 0.055) for 6962 data (I > 3.0sigma(I)). Crystal data for [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(2)(CNXyl)]O(3)SCF(3).Me(2)CHC(O)Me (7) at 295 K: monoclinic space group P2(1)/n (No. 14) with a = 14.951(2) ?, b = 12.4180(19) ?, c = 40.600(5) ?, beta = 89.993(11) degrees, V = 7537(3) ?(3), and Z = 4. The structure was refined to R = 0.074 (R(w) = 0.088) for 6595 data (I > 3.0sigma(I)).     

Reactivity of the isolable disilene R*PhSi=SiPhR* (R* = SitBu3)

The disilene R*PhSi=SiPhR* (R* = supersilyl = SitBu3), which can be quantitatively prepared by dehalogenation of the disilane R*PhClSi-SiBrPhR* with NaR* (yellow, water- and air-sensitive crystals; decomp at ca. 70 degrees C; Si=Si distance 2.182 A), is comparatively reactive. It transforms 1) with Cl2, Br2, HCl, HBr, and HOH under 1,2-addition into disilanes R*PhXSi-SiX'PhR* (X/X' = Hal/Hal, H/Hal, H/OH), 2) with O2, S8, and Sen under insertion into 1,3-disiletanes R*PhSi(-Y-)2SiPhR* (Y = O, S, Se), 3) with Me2C=CH2 under ene reaction into the disilane R*PhRSi-SiHPhR* (R = CH2-CMe=CH2), 4) with N2O, Ten, tBuN identical to C, and Me3SiN=N=N under [2 + 1] cycloaddition into disiliranes -R*PhSi-Y-SiPhR*- (Y = O, Te, C=NtBu, NSiMe3; P4 adds 2 molecules of disilene), 5) with CO2, COS, PhCHO, and Ph2CS under [2 + 2] cycloaddition into disiletanes -R*PhSi-SiPhR*-Y-CO- (Y = O, S) as well as -R*PhSi-SiPhR*-Y-CRPh- (Y/R = O/H, S/Ph), 6) with CS2 and CSe2 under [2 + 3] cycloaddition into ethenes R*2Ph2Si2Y2C = CY2Si2Ph2R*2 (Y = S, Se), and 7) with CH2 = CMe-CMe=CH2 and Ph2CO under [2 + 4] cycloaddition into "Diels-Alder adducts". X-ray structure analyses of seven of these compounds are presented.     

Trajectory calculations of OH radical- and Cl atom-initiated reaction of glyoxal: atmospheric chemistry of the HC(O)CO radical

On-the-fly quasi-classical trajectory calculations using the density functional method were carried out to investigate the dynamics of the HC(O)CO radical, formed by OH radical- and Cl atom-initiated reactions of glyoxal at 298 K. The energy difference between the A' HC(O)CO radical, formed immediately after H atom abstraction, and the most stable A″ HC(O)CO radical is estimated to be 6.0 kcal mol(-1). The surplus energy followed by relaxation from A' HC(O)CO to A″ HC(O)CO goes to internal energy of the nascent HC(O)CO radicals and causes prompt decomposition into HCO + CO. The average internal energy partitioned into the HC(O)CO radical is higher in the OH reaction than in the Cl reaction, in accordance with exothermicity of the reactions. A fraction of the nascent HC(O)CO radicals (91% for the OH reaction and 47% for the Cl reaction) promptly decomposes into HCO and CO within 2.5 ps. The remaining HC(O)CO radicals, which do not undergo prompt decomposition, decompose thermally or add with O(2) in the presence of O(2). I re-evaluated the previous two experiment results of the product yield ratio [CO]/[CO(2)] vs. [O(2)](-1) in the Cl atom-initiated reaction, in light of the reaction mechanism involving prompt decomposition. The two results give 9.5 × 10(6) s(-1) and 1.08 × 10(7) s(-1) for the thermal decomposition rate and 47% and 41% for the fraction of prompt decomposition in the Cl atom-initiated reaction, in good agreement with the present trajectory calculation.     

Syntheses of chromium pentacarbonyl derivatives of arsenic(V) and antimony(V). contrasting chemical reactivity with organic halogen derivatives

We have synthesized a new series of chromium-group 15 dihydride and hydride complexes [H(2)As(Cr(CO)(5))(2)](-) (1) and [HE(Cr(CO)(5))(3)](2)(-) (E = As, 2a; E = Sb, 2b), which represent the first examples of group 6 complexes containing E-H fragments. The contrasting chemical reactivity of 2a and 2b with organic halogen derivatives is demonstrated. The reaction of 2a with RBr (R = PhCH(2), HC triple bond CCH(2)) produces the RX addition products [(R)(Br)As(Cr(CO)(5))(2)](-) (R = PhCH(2), 3; R = C(3)H(3), 4), while the treatment of 2b with RX (RX = PhCH(2)Br or HC triple bond CCH(2)Br, CH(3)(CH(2))(5)C(O)Cl) forms the halo-substituted complexes [XSb(Cr(CO)(5))(3)](2-) (X = Br, 5; X = Cl, 6). Moreover, the dihaloantimony complexes [XX'Sb(Cr(CO)(5))(2)](-) can be obtained from the reaction of 2b with the appropriate organic halides. In this study, a series of organoarsenic and antimony chromium carbonyl complexes have been synthesized and structurally characterized and the role of the main group on the formation of the resultant complexes is also discussed.     

Variable-energy photoelectron spectroscopy of substituted rhenium and manganese pentacarbonyls: molecular orbital assignments and the interatomic resonant effect

High-resolution variable-energy photoelectron spectra of M(CO)5X [M = Re, X = Re(CO)5, Cl, Br, and I; and M = Mn, X = Mn(CO)5 and Br] are reported. Tunable synchrotron radiation is used to distinguish the Re 5d and Br 4p orbital based peaks for the controversial Re(CO)5Br. Our results provide firm molecular orbital assignments for all of these molecules. The valence orbital in the ordering of ionization energies for M(CO)5Cl (M = Mn and Re) and Mn(CO)5Br is a 1(M-X) > e(X) > b2(M) > e(M); but for M(CO)5I (M = Mn and Re) and Re(CO)5Br the ordering is a1(M-X) > e(M) > b2(M) > e(X). The crossover of the HOMO in the Re molecules due to the change in the halogen electronegativities occurs at Re(CO)5Br. The metal np-->nd resonance is observed for all of these molecules. For molecules like M2(CO)10 (M = Re and Mn) and Mn(CO)5Br, the observation of this np-->nd resonance is useful in assigning the metal nd based orbitals in their valence level spectra. However, for molecules like Re(CO)5X (X = Br and Cl), a np-->nd type resonance is observed on bands arising from both Re 5d and halogen mp based orbitals. This new resonant effect on the ligand-based orbitals is shown to be mainly due to the interatomic resonant effect. The core and valence level chemical shifts of these compounds are treated using Jolly's approach to confirm the assignments for the valence level spectra of some of these molecules. The high-resolution inner valence and core level spectra of these compounds are reported. Broadening of Re 4f, Br 3d, and I 4d core level spectra is discussed. The Auger peaks are observed in the high-resolution, high-intensity Br 3d of Re(CO)5Br and I 4d of Re(CO)5I spectra.     

Hydrolyse und Halogenidaustausch von Pentahalogenomonocarbonylosmaten(III)

Hydrolysis and Halide Exchange of Pentahalogenomonocarbonyl Osmates(III) The aquo complexes [OsX₄(CO)(H₂O)]^?, [OsX₃(CO)(H₂O)] and [OsX₂(CO)(H₂O)₃]⁺, X ? Cl, Br, I, produced by the stepwise hydrolysis of [OsX₅(CO)]^2?, are isolated as pure solutions by ionophoresis and characterized by their absorption spectra. Due to stability of the monaquo complexes and the different trans-effect of the halides it is possible to prepare the mixed complexes [OsX_4–nY_n(CO)(H₂O)]^?, X ≠ Y = Cl, Br, I, n = 1–3, and for n = 2 the pure stereoisomers are formed. A systematic shift is found in charge-transfer bands to the shorter wavelengths when the halides are replaced by H₂O, I by Br or Cl and Br by Cl.