Reactivity of 2,3-bis(2-pyridyl)pyrazine with [Re2(CO)8(CH3CN)2]: Molecular structures of [Re2(CO)8(C14H10N4)] and [Re2(CO)8(C14H10N4)Re2(CO)8]

The reaction of the labile compound [Re₂(CO)₈(CH₃CN)₂] with 2,3-bis(2-pyridyl)pyrazine in dichloromethane solution at reflux temperature afforded the structural dirhenium isomers [Re₂(CO)₈(C₁₄H₁₀N₄)] (1 and 2), and the complex [Re₂(CO)₈(C₁₄H₁₀N₄)Re₂(CO)₈] (3). In 1, the ligand is σ,σ′-N,N′-coordinated to a Re(CO)₃ fragment through pyridine and pyrazine to form a five-membered chelate ring. A seven-membered ring is obtained for isomer 2 by N-coordination of the 2-pyridyl groups while the pyrazine ring remains uncoordinated. For 2, isomers 2a and 2b are found in a dynamic equilibrium ratio [2a]/[2b]  =  7 in solution, detected by ¹H NMR (−50 °C, CD₃COCD₃), coalescence being observed above room temperature. The ligand in 3 behaves as an 8e-donor bridge bonding two Re(CO)₃ fragments through two (σ,σ′-N,N′) interactions. When the reaction was carried out in refluxing tetrahydrofuran, complex [Re₂(CO)₆(C₁₄H₁₀N₄)₂] (4) was obtained in addition to compounds 1-3. The dinuclear rhenium derivative 4 contains two units of the organic ligand σ,σ′-N,N′-coordinated in a chelate form to each rhenium core. The X-ray crystal structures for 1 and 3 are reported.     

Cp2Ti{[OC(O)C5H4]Cr(CO)2NO]}2 and Cp2Ti{[(OC(O)C5H4]Cr(NO)2X}2 syntheses and spectra of chromium-titanium complexes bridged by carboxylate substituted cyclopentadienyl group

Complete demethylation of Cp₂Ti(CH₃)₂ in dichloromethane with 2 M equivalent of [η⁵-(C₅H₄COOH)]Cr(CO)₂NO (5), [η⁵-(C₅H₄COOH)]Cr(NO)₂X] (X = Cl 6, X = I 7), and [η⁵-(C₅H₄COOH)]W(CO)₃CH₃ (8); gives Cp₂Ti{[OC(O)C₅H₄]Cr(CO)₂NO}₂ (13), Cp₂Ti{[OC(O)C₅H₄]Cr(NO)₂Cl}₂ (14), Cp₂Ti{[OC(O)C₅H₄]Cr(NO)₂I}₂ (15),and Cp₂Ti{[OC(O)C₅H₄]W(CO)₃CH₃}₂ (16), respectively. The chemical shifts of C(2)-C(5) carbon atoms of compounds 13-15 have been assigned using two-dimensional HetCOR NMR spectroscopy. The assigned chemical shifts were compared with the NMR data of their analogues of ferrocene, and the opposite correlation on the assignments was observed for cynichrodenoyl moieties.     

Electrochemical, EPR and computational results on [Fe2Cp2(CO)2]-based complexes with a bridging hydrocarbyl ligand

The dimetallacyclopentenone complexes [Fe₂Cp₂(CO)(μ−CO){μ−η¹:η³−C_αHC_β(R)C(O)}] (R = CH₂OH, 1a; R = CMe₂OH, 1b; R = Ph, 1c) were prepared by photolytic reaction of [Fe₂Cp₂(CO)₄] with alkyne according to the literature procedure. The X-ray and the electrochemical characterization of 1c are presented. The μ-allenyl compound [Fe₂Cp₂(CO)₂(μ−CO){μ−η¹:η²_α,β−C_αHC_βCMe₂][BF₄] ([2][BF₄]), obtained by reaction of 1b with HBF₄, underwent monoelectron reduction to give a radical species which was detected by EPR at room temperature. The EPR signal has been assigned to [Fe₂Cp₂(CO)₂(μ−CO){μ−η¹:η²_α,β-C_αHC_βCMe₂}], [2]^•. The molecular structures of [2]⁺ and [2]^• were optimized by DFT calculations. The unpaired electron in [2]^• is localized mainly at the metal centers and, coherently, [2]^• does not undergo carbon-carbon dimerization, by contrast with what previously observed for the μ-vinyl radical complex [Fe₂Cp₂(CO)₂(μ−CO){μ−η¹:η²-CHCH(Ph)}]^•, [3]^•. Electron spin density distributions similar to the one of [2]^• were found for the μ-allenyl radical complexes [Fe₂Cp₂(CO)₂(μ-CO){μ-η¹:η²_α,β-C_αHC_βC(R¹)(R²)}]^• (R¹ = R² = H, [4]^•; R¹ = H, R² = Ph, [5]^•; R¹ = R² = Ph, [6]^•).     

Syntheses of platinum(II) complexes of cyclo-octenyl group and isolation of a self-assembled oxo-bridged macrocyclic complex [Pt4(Spy)4(C8H12-O-C8H12)2]

Reactions of [Pt₂(μ-Cl)₂(C₈H₁₂OMe)₂] (1) (C₈H₁₂OMe = 8-methoxy-cyclooct-4-ene-1-yl) with various anionic chalcogenolate ligands have been investigated. The reaction of 1 with Pb(Spy)₂ (HSpy = pyridine-2-thiol) yielded a binuclear complex [Pt₂(Spy)₂(C₈H₁₂OMe)₂] (2). A trinuclear complex [Pt₃(Spy)₄(C₈H₁₂OMe)₂] (3) was isolated by a reaction between 2 and [Pt(Spy)₂]_n. The reaction of 1 with HSpy in the presence of NaOMe generated 2 and its demethylated oxo-bridged tetranuclear complex [Pt₄(Spy)₄(C₈H₁₂-O-C₈H₁₂)₂] (4). Treatment of 1 with ammonium diisopropyldithiophosphate completely replaced C₈H₁₂OMe resulting in [Pt(S₂P{OPrⁱ}₂)₂] (5), whereas non-rigid 5-membered chelating ligand, Me₂NCH₂CH₂E⁻, produced mononuclear complexes [Pt(ECH₂CH₂NMe₂)(C₈H₁₂OMe)] (E = S (6), Se (7)). These complexes have been characterized by elemental analyses, NMR (¹H, ¹³C{¹H}, ¹⁹⁵Pt{¹H}) and absorption spectroscopy. Molecular structures of 2, 3, 4, 5 and 7 were established by single crystal X-ray diffraction analyses. Thermolysis of 2, 6 and 7 in HDA gave platinum nanoparticles.     

Solubility of trans-Co2(CO)6 [3,5-bis(CF3)C6H3P(i-C3H7)2] in dense carbon dioxide

The title compound (1) was prepared by the reaction of 3,5-bis(CF₃)C₆H₃P(i-C₃H₇)₂ (L1) and Co₂(CO)₈. Its solubility in supercritical carbon dioxide was measured at varying temperatures and pressures using a modified analytical extraction device. Solubility data were determined in the temperature and pressure ranges between 40 and 70 °C and between 100 and 300 bar, respectively. The solubility of 1 is lower compared to (p-CF₃C₆H₄)₃P, but much higher than for transition metal complexes bearing phosphines without fluorinated substituents.     

Reactions of Mo(II)-tetraphosphine complex [MoCl2{meso-o-C6H4(PPhCH2CH2PPh2)2}] with a series of small molecules

Reactions of Mo(II)-tetraphosphine complex [MoCl₂(κ⁴-P4)] (2; P4 = meso-o-C₆H₄(PPhCH₂CH₂PPh₂)₂) with a series of small molecules have been investigated. Thus, treatment of 2 with alkynes RCCR′ (R = Ph, R′ = H; R = p-tolyl, R′ = H; R = Me, R′ = Ph) in benzene or toluene gave neutral mono(alkyne) complexes [MoCl₂(RCCR′)(κ³-P4)] containing tridentate P4 ligand, which were converted to cationic complexes [MoCl(RCCR′)(κ⁴-P4)]Cl having tetradentate P4 ligand upon dissolution into CDCl₃ or CD₂Cl₂. The latter complexes were available directly from the reactions of 2 with the alkynes in CH₂Cl₂. On the other hand, treatment of 2 with 1 equiv. of XyNC (Xy = 2,6-Me₂C₆H₃) afforded a seven-coordinate mono(isocyanide) complex [MoCl₂(XyNC)(κ⁴-P4)] (7), which reacted further with XyNC to give a cationic bis(isocyanide) complex [MoCl(XyNC)₂(κ⁴-P4)]Cl (8). From the reaction of 2 with CO, a mono(carbonyl) complex [MoCl₂(CO)(κ⁴-P4)] (9) was obtained as a sole isolable product. Reaction of 9 with XyNC afforded [MoCl(CO)(XyNC)(κ⁴-P4)]Cl (10a) having a pentagonal-bipyramidal geometry with axial CO and XyNC ligands, whereas that of 7 with CO resulted in the formation of a mixture of 10a and its isomer 10b containing axial CO and Cl ligands. Structures of 7 and 9 as well as [MoCl(XyNC)₂(κ⁴-P4)][PF₆](8′) and [MoCl(CO)(XyNC)(κ⁴-P4)][PF₆] (10a′) derived by the anion metathesis from 8 and 10a, respectively, were determined in detail by the X-ray crystallography.     

Cyclopentadienyl tungsten complexes with thiocarboxylate and thiosulfonate ligands: Structures of CpW(CO)3SCOPh and CpW(CO)3SSO2-4-C6H4Cl

Treatment of the hydrosulfido tungsten complex CpW(CO)₃SH with acid chlorides (RCOCl) or sulfonyl chlorides (RSO₂Cl) affords CpW(CO)₃SCOR (1) [R = Me (a), CH₂Cl (b), Ph (c), 4-C₆H₄NO₂ (d)] and CpW(CO)₃SSO₂R (2) [R = Me (a), Ph (b), 4-C₆H₄Cl (c), 4-C₆H₄NO₂ (d)], respectively. The novel complexes, 1 and 2, were fully characterized by elemental analyses, IR and ¹H NMR spectroscopy. The solid state structures of CpW(CO)₃SCOPh (1c) and CpW(CO)₃SSO₂-4-C₆H₄Cl (2c) were determined by an X-ray crystal structure analysis.     

C-H activation of benzene with CpRu(CO)2CH3

Irradiation of Cp^∗Ru(CO)₂CH₃ (1) in C₆D₆ at room temperature yields Cp^∗Ru(CO)₂C₆D₅ and CH₃D (where Cp^∗ = n⁵-C₅Me₅). Cp^∗Ru(CO)₂CD₃ (2) has also been prepared and similar irradiation in C₆H₆ yields Cp^∗Ru(CO)₂C₆H₅ (3) and CD₃H. This latter reaction confirms that it is the methyl group bonded to ruthenium that is involved in the C-H activation process and not the methyl groups on the Cp^∗ ligand system. The compound Cp^∗Ru(CO)₂C₆H₅ (3) has been prepared for the first time in good yield by the reaction of Cp^∗Ru(CO)₂Br with NaBPh₄. X-ray crystal structures of both Cp^∗Ru(CO)₂CH₃ (1) and Cp^∗Ru(CO)₂C₆H₅ (3) have been determined and the results are reported and discussed.     

Novel sandwich complexes of zirconium [C9H5(SiMe3)2](C5Me4R)ZrCl2 (R = CH3, CH2CH2NMe2): Synthesis and reduction behavior

Novel half-sandwich [C₉H₅(SiMe₃)₂]ZrCl₃ (3) and sandwich [C₉H₅(SiMe₃)₂](C₅Me₄R)ZrCl₂ (R = CH₃ (1), CH₂CH₂NMe₂ (2)) complexes were prepared and characterized. The reduction of 2 by Mg in THF lead to (η⁵-C₉H₅(SiMe₃)₂)[η⁵:η²(C,N)-C₅Me₄CH₂CH₂N(Me)CH₂]ZrH (7). The structure of 7 was proved by NMR spectroscopy data. Hydrolysis of 2 resulted in the binuclear complex ([C₅Me₄CH₂CH₂NMe₂]ZrCl₂)₂O (6). The crystal structures of 1 and 6 were established by X-ray diffraction analysis.     

Alkynyl Ti-M complexes based on M(CO)4 and MO2 building blocks (M = Mo, W)

The synthesis and properties of heterobimetallic Ti-M complexes of type {[[Ti](μ-η¹:η²-CCSiMe₃)][M(μ-η¹:η²-CCSiMe₃)(CO)₄]} (M = Mo: 5, [Ti] = (η⁵-C₅H₅)₂Ti; 6, [Ti] = (η⁵-C₅H₄SiMe₃)₂Ti; M = W: 7, [Ti] = (η⁵-C₅H₅)₂Ti; 8, [Ti] = (η⁵-C₅H₄SiMe₃)₂Ti) and {[Ti](μ-η¹:η²-CCSiMe₃)₂}MO₂ (M = Mo: 13, [Ti] = (η⁵-C₅H₅)₂Ti; 14, [Ti] = (η⁵-C₅H₄SiMe₃)₂Ti). M = W: 15, [Ti] = (η⁵-C₅H₅)₂Ti; 16, [Ti] = (η⁵-C₅H₄SiMe₃)₂Ti) are reported. Compounds 5-8 were accessible by treatment of [Ti](CCSiMe₃)₂ (1, [Ti] = (η⁵-C₅H₅)₂Ti; 2, [Ti] = (η⁵-C₅H₄SiMe₃)₂Ti) with [M(CO)₅(thf)] (3, M = Mo; 4, M = W) or [M(CO)₄(nbd)] (9, M = Mo; 10, M = W; nbd = bicyclo[2.2.1]hepta-2,5-diene), while 13-16 could be obtained either by the subsequent reaction of 1 and 2 with [M(CO)₃(MeCN)₃] (11, M = Mo; 12, M = W) and oxygen, or directly by oxidation of 5-8 with air. A mechanism for the formation of 5-8 is postulated based on the in-situ generation of [Ti](CCSiMe₃)((η²-CCSiMe₃)M(CO)₅), {[Ti](μ-η¹:η²-CCSiMe₃)₂}-M(CO)₄, and [Ti](μ-η¹:η²-CCSiMe₃)((μ-CCSiMe₃)M(CO)₄) as a result of the chelating effect exerted by the bis(alkynyl) titanocene fragment and the steric constraints imposed by the M(CO)₄ entity.The molecular structure of 5 in the solid state were determined by single crystal X-ray diffraction analysis. In doubly alkynyl-bridged 5 the alkynides are bridging the metals Ti and Mo as a σ-donor to one metal and as a π-donor to the other with the [Ti](CCSiMe₃)₂Mo core being planar.     

Syntheses and spectra of chromium-titanium complexes bridged by carboxylate substituted cyclopentadienyl group: The structure of Cp2Ti(CH3){[OC(O)C5H4]Cr(NO)2Cl}

Mono-demethylation of Cp₂Ti(CH₃)₂ in dichloromethane with 1 M equivalent of [η⁵-(C₅H₄COOH)]Cr(CO)₂NO (5), [η⁵-(C₅H₄COOH)]Cr(NO)₂X] (X = Cl 6, X = I 7) and [η⁵-(C₅H₄COOH)]W(CO)₃CH₃ (8) gives Cp₂Ti(CH₃){[OC(O)C₅H₄]Cr(CO)₂NO} (9), Cp₂Ti(CH₃){[OC(O)C₅H₄]Cr(NO)₂Cl} (10), Cp₂Ti(CH₃){[OC(O)C₅H₄]Cr(NO)₂I} (11) and Cp₂Ti(CH₃){[OC(O)C₅H₄]W(CO)₃CH₃} (12), respectively. The structure of 10 has been solved by X-ray diffraction studies. One of the nitrosyl groups is located at the site away from the exocyclic carbonyl carbon of the Cp(Cr) ring with twist angle of 178.1°. All the data reveals that Cp₂Ti(CH₃)- is a strong electron-donating group. The opposite correlation was observed on the chemical shift assignments of C(2)-C(5) in compounds 5-12, using HetCOR NMR spectroscopy, as compared with the NMR data of their ferrocene analogues. The electron density distribution in the cyclopentadienyl ring is discussed on the basis of ¹³C NMR data and those of 10 are compared with the calculations via density functional B3LYP correlation- exchange method.     

Synthesis and X-ray structural characterization of the triphenylphosphine derivative of the closo-dodecaborate anion, closo-[B12H11P(C6H5)3][N(n-C4H9)4]

The reaction of a molar excess of closo-[B₁₂H₁₁I][N(n-C₄H₉)₄]₂ (1) with tetrakis(triphenylphosphine)palladium (0), Pd(0)L₄, yields to the formation of the title monoanionic compound, closo-[1-B₁₂H₁₁P(C₆H₅)₃][N(n-C₄H₉)₄] (2). The structure of 2 was determined by X-ray diffraction analysis performed on a single crystal. The mechanism of formation of 2 is also discussed. We suggested a two-step mechanism for the formation of 2 consisting in a oxidative addition of the palladium complex followed by a reductive elimination involving P(C₆H₅)₃ and assisted by Na₂CO₃. To our knowledge, this is the first example of monosubstitution of B₁₂ with formation of boron-phosphorus bond.     

Catalytic oxidation of diorganotin(IV) carboxylates to mixed-ligand monoalkyltin(IV) carboxylates by Ag and structure characterization of the mixed-ligand monoalkyltin(IV) 2-pyridinecarboxylate (2-ClPhCH2)Sn(2-ClPhCO2)(O2CC5H4N-2)2

The complexes of the type (ArCH₂)₂SnO were catalytic-oxygenated by Ag⁺ and yielded mixed-ligand organotin(IV) complexes (ArCH₂)(2-C₅H₄NCO₂)₂(ArCOO)tin(IV) (Ar = C₆H₅ (1), 2-ClC₆H₄ (2), 2-CNC₆H₄ (3), 4-ClC₆H₄ (4), 4-CNC₆H₄ (5), 2-FC₆H₄ (6)). The complexes 1-6 are characterized by elemental analyses, IR and NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopies. Single X-ray crystal structure analysis has been determined, which reveals that the center tin atom of complex 2 is seven-coordinated geometry.     

A ferrocenyl-bridged intramolecularly coordinated bis(diorganostannylene): Synthesis, molecular structure and reactivity of [4-t-Bu-2,6-{P(O)(O-i-Pr)2C6H2Sn}C5H4]2Fe

The intramolecularly coordinated heteroleptic stannylene [4-t-Bu-2,6-{P(O)(O-i-Pr)₂}₂C₆H₂]SnCl serves as synthon for the synthesis of the ferrocenyl-bridged bis(diorganostannylene) [4-t-Bu-2,6-{P(O)(O-i-Pr)₂}₂C₆H₂SnC₅H₄]₂Fe (1) which in turn reacts with W(CO)₆ and Cr(CO)₄(C₇H₈) to provide the corresponding transition metal complexes [4-t-Bu-2,6-{P(O)(O-i-Pr)₂}₂C₆H₂Sn{W(CO)₅}C₅H₄]₂Fe (2) and [4-t-Bu-2,6-{P(O)(O-i-Pr)₂}₂C₆H₂SnC₅H₄]₂Fe · Cr(CO)₄ (3), respectively. Reaction of compound 1 with sulphur and atmospheric moisture gave, under partial tin-carbon and oxygen-carbon bond cleavage, a tetranuclear organotin-oxothio cluster 5. All compounds were characterized by ¹H, ¹³C, ³¹P, and ¹¹⁹Sn NMR, and IR spectroscopy, as well as by single-crystal X-ray diffraction analysis. Compounds 1 and 3 were also investigated by Mössbauer spectroscopy. Cyclovoltametric studies reveal the influence of the organostannyl moieties on the redox-behaviour of compounds 1-3 in comparison with unsubstituted ferrocene.     

Reaction of nido-1,2-(CpRuH)2B3H7 with ethynylferrocene to yield new metallacarboranes

Addition of ethynylferrocene to nido-1,2-(Cp^∗RuH)₂B₃H₇ (1) at ambient temperature leads to nido-1,2-(Cp^∗Ru)₂(1,5-μ-C{Fc}Me)B₃H₇ (2, 3) and closo-4-Fc-1,2-(Cp^∗RuH)₂-4,6-C₂B₂H₃ (4). Compounds 2 and 3 represent a pair of geometric isomers, nido-species in which the regiochemistry of the alkyne reduction conforms to the Markovnikoff rule. Compound 4 is an octahedral structure in which the inserted alkyne is on an open face of the closo cluster.     

New orthopalladated complexes of phosphorus ylides: Crystal structure of [Pd{CH{P(C7H6)(p-tolyl)2}COCH3}Cl{P(p-tolyl)3}]

This work reports on the preparation of the complexes [PdCl₂(Y¹)₂], [PdCl₂(Y²)₂] (Y¹ = (p-tolyl)₃PCHCOCH₃ (1a); Y² = Ph₃PCHCO₂CH₂Ph (1b)), [Pd{CHP(C₇H₆)(p-tolyl)₂COCH₃}(μ-Cl)]₂ (2a), [Pd{CHP(C₆H₄)Ph₂CO₂CH₂Ph}(μ-Cl)]₂ (2b), [Pd{CH{P(C₇H₆)(p-tolyl)₂}COCH₃}Cl(L)] (L = PPh₃ (3a), P(p-tolyl)₃ (4a)) and [Pd{CH{P(C₆H₄)Ph₂}CO₂CH₂Ph}Cl(L)] (L = PPh₃ (3b), P(p-tolyl)₃ (4b)). Orthometallation and ylide C-coordination in complexes 2a–4b are demonstrated by an X-ray diffraction study of 4a.     

Structural investigations on new iron-acyl derivatives of B(C6F5)3

Reactions between [Fe(η-C₅H₅)(MeCO)(CO)(L)], L = PPh₃ (1), PMe₃ (2), PPhMe₂ (3), PCy₃ (4), CO (5), and B(C₆F₅)₃ give new complexes [Fe(η-C₅H₅){MeCOB(C₆F₅)₃}(CO)(L)] L = PPh₃ (7), PMe₃ (8), PPhMe₂ (9), PCy₃ (10), CO (11), where B(C₆F₅)₃ coordinates selectively to the O-acyl groups. Hydrolysis of 7 gives [Fe(η-C₅H₅){HOB(C₆F₅)₃}(CO)(PPh₃)] (6). The X-ray structures of 6, 8 and 11 have been determined. Calculations, using density functional theory, demonstrate that the charge transfer to the acyl group on Lewis acid coordination is more significant in the σ than the π system. Both effects lead to a lengthening of the acyl C-O bond thus π populations cannot be inferred from the distance changes.     

Synthesis and characterization of hetero-binuclear Co-Rh complexes [CpCoS2C2(B9H10)][Rh(COD)] and [CpCoSe2C2(B10H10)][Rh(COD)]

Two hetero-binuclear complexes [Cp^∗CoS₂C₂(B₉H₁₀)][Rh(COD)] (2a) and [Cp^∗CoSe₂C₂(B₁₀H₁₀)][Rh(COD)] (2b) [Cp^∗ = η⁵-pentamethylcyclopentadienyl, COD = cyclo-octa-1,5-diene (C₈H₁₂)] were synthesized by the reactions of half-sandwich complexes [Cp^∗CoE₂C₂(B₁₀H₁₀)] [E = S (1a), Se (1b)] with low valent transition metal complexes [Rh(COD)(OEt)]₂ and [Rh(COD)(OMe)]₂. Although the reaction conditions are the same, the structures of two products for dithiolato carborane and diselenolato carborane are different. The cage of the carborane in 2a was opened; However, the carborane cage in 2b was intact. Complexes 2a and 2b have been fully characterized by ¹H, ¹¹B NMR and IR spectroscopy, as well as by elemental analyses. The molecular structures of 2a and 2b have been determined by single-crystal X-ray diffraction analyses and strong metal-metal interactions between cobalt and rhodium atoms (2.6260 Å (2a) and 2.7057 Å (2b)) are existent.     

Solvent-dependent formation of two different Cd(II) complexes with p-BrC6H4C(S)NHP(O)(OiPr)2 (HL). Crystallographic modification of Cd(HL)2L2

Reaction of the potassium salt of N-(diisopropoxyphosphoryl)-p-bromothiobenzamide p-BrC₆H₄C(S)NHP(O)(OiPr)₂ (HL) with Cd(II) cations in freshly dried and distilled EtOH leads exclusively to the complex [Cd(p-BrC₆H₄C(S)NH₂-S)(L-O,S)₂] ([Cd(L^I)L₂]), while the same reaction in H₂O leads to the complex [Cd(HL-O)₂(L-O,S)₂] ([Cd(HL)₂L₂]). The corresponding reactions with Zn(II) always lead to the complex [Zn(L-O,S)₂] ([ZnL₂]) regardless of the solvent. The crystal structure of [Cd(HL)₂L₂]^.2/3H₂O reveals to be a polymorph to the previously reported anhydrous [Cd(HL)₂L₂].     

Reactions of 1,8-bis(diphenylphosphino)naphthalene with Os3(CO)12: C-H and C-P bond cleavage reactions

Reactions of Os₃(CO)₁₂ with 1,8-bis(diphenylphosphino)naphthalene (dppn) are described. Crystallographically characterised complexes isolated from a reaction carried out in refluxing toluene are Os₃(μ-H)₂{μ-PPh₂(nap)PPh(C₆H₄)}₂(CO)₆ (1), Os₃(μ-H){μ₃-PPh₂(nap)PPh(C₆H₄)}(CO)₈ (2) and Os₂(μ-PPh₂){μ-PPh₂(nap)}(CO)₅ (3) (nap=1,8-C₁₀H₆), while at r.t. in the presence of ONMe₃, only Os₃(CO)₁₁{PPh₂(1-C₁₀H₇)} (4) was isolated. While 1 and 2 contain ligands formed by metallation of a Ph group of dppn, as found also in complexes obtained from dppn and Ru₃(CO)₁₂, ligands in 3 and 4 are formed by cleavage of a P-nap bond, not found in the Ru series.