Synthesis and structural characterization of ferrocenyl indenyl derivatives

In this study, four ferrocenyl indenyl derivatives, C₉H₇–C≡C–Fc (1), C₉H₇–C≡C–Ph–Fc (2), C₉H₇–C≡C–Ph–C≡C–Fc (3), and C₉H₇–Ph–C≡C–Fc (4) (where C₉H₇=indenyl; Fc=C₅H₅FeC₅H₄; Ph=C₆H₅), have been synthesized by Sonogashira and Suzuki cross-coupling reactions and characterized by elemental analysis, and FT-IR, ¹H, ¹³C-NMR, and MS spectroscopic methods, respectively. The molecular structures of 1, 2, and 4 were determined by X-ray single crystal diffraction. Two molecules appeared in the crystal structure of 4, and they interact through an intermolecular hydrogen bond. The electrochemical redox potential differences in 1–4 were investigated using cyclic voltammetry and calculations.     

Structural Studies of Some Compounds Containing C2 Fragments Attached to Various Metal‐Ligand End‐Groups

The preparation, characterisation and single‐crystal XRD molecular structure determinations of four complexes containing –CC–ML_n end‐groups, namely Ru{C≡CFc′(I)}(dppe)Cp ( 1 ), the vinylidene [Os(=C=CH₂)(PPh₃)₂Cp]PF₆ ( 2 ), trans‐Pt(C≡CC₆H₄‐4‐C≡CPh){C≡CC₆H₄‐4‐C₂Ph[Co₂(μ‐dppm)(CO)₄]}(PPh₃)₂ ( 3 ), and C₆H₄{μ₃‐C₂[AuRu₃(CO)₉(PPh₃)]}₂‐1,4 ( 4 ) are reported. In these compounds a range of –CC– environments is found, extending from the σ‐bonded alkynyl group in 1 to examples where the C₂ unit interacts with either a proton (in vinylidene 2 ), by bridging a dicobalt carbonyl moiety (in 3 ) or the AuRu₃ cluster in 4 . Changes in geometry are rationalised by considering the various bonding modes.     

Further Evidence for ‘Extended’ Cumulene Complexes: Derivatives from Reactions with Halide Anions and Water

Reactions of [Ru{C=C(H)-1,4-C₆H₄C≡CH}(PPh₃)₂Cp]BF₄ ([ 1 a ]BF₄) with hydrohalic acids, HX, results in the formation of [Ru{C≡C-1,4-C₆H₄-C(X)=CH₂}(PPh₃)₂Cp] [X=Cl ( 2 a-Cl ), Br ( 2 a-Br )], arising from facile Markovnikov addition of halide anions to the putative quinoidal cumulene cation [Ru(=C=C=C₆H₄=C=CH₂)(PPh₃)₂Cp]⁺. Similarly, [M{C=C(H)-1,4-C₆H₄-C≡CH}(LL)Cp ]BF₄ [M(LL)Cp’=Ru(PPh₃)₂Cp ([ 1 a ]BF₄); Ru(dppe)Cp* ([ 1 b ]BF₄); Fe(dppe)Cp ([ 1 c ]BF₄); Fe(dppe)Cp* ([ 1 d ]BF₄)] react with H⁺/H₂O to give the acyl-functionalised phenylacetylide complexes [M{C≡C-1,4-C₆H₄-C(=O)CH₃}(LL)Cp’] ( 3 a – d ) after workup. The Markovnikov addition of the nucleophile to the remote alkyne in the cations [ 1 a–d ]⁺ is difficult to rationalise from the vinylidene form of the precursor and is much more satisfactorily explained from initial isomerisation to the quinoidal cumulene complexes [M(=C=C=C₆H₄=C=CH₂)(LL)Cp’]⁺ prior to attack at the more exposed, remote quaternary carbon. Thus, whilst representative acetylide complexes [Ru(C≡C-1,4-C₆H₄-C≡CH)(PPh₃)₂Cp] ( 4 a ) and [Ru(C≡C-1,4-C₆H₄-C≡CH)(dppe)Cp*] ( 4 b ) reacted with the relatively small electrophiles [CN]⁺ and [C₇H₇]⁺ at the β-carbon to give the expected vinylidene complexes, the bulky trityl ([CPh₃]⁺) electrophile reacted with [M(C≡C-1,4-C₆H₄-C≡CH)(LL)Cp’] [M(LL)Cp’=Ru(PPh₃)₂Cp ( 4 a ); Ru(dppe)Cp* ( 4 b ); Fe(dppe)Cp ( 4 c ); Fe(dppe)Cp* ( 4 d )] at the more exposed remote end of the carbon-rich ligand to give the putative quinoidal cumulene complexes [M{C=C=C₆H₄=C=C(H)CPh₃}(LL)Cp’]⁺, which were isolated as the water adducts [M{C≡C-1,4-C₆H₄-C(=O)CH₂CPh₃}(LL)Cp’] ( 6 a–d ). Evincing the scope of the formation of such extended cumulenes from ethynyl-substituted arylvinylene precursors, the rather reactive half-sandwich (5-ethynyl-2-thienyl)vinylidene complexes [M{C=C(H)-2,5-^cC₄H₂S-C≡CH}(LL)Cp’]BF₄ ([ 7 a – d ]BF₄ add water readily to give [M{C≡C-2,5-^cC₄H₂S-C(=O)CH₃}(LL)Cp’] ( 8 a – d )].     

Syntheses,crystal structures and biological activity of the dialkytin complexes based on 2-oxo-3-phenylpropionic acid salicyloylhydrazone

Three new dialkytin complexes, {[o-OH–C₆H₄(O)C=N–N=C(CH₂Ph)COO](n-Bu₂Sn)}_n (1), {[o-OH–C₆H₄(O)C=N–N=C(CH₂Ph)COO](MeOH)(p-MeC₆H₅CH₂)₂Sn}₂ (2), and {[o-OH–C₆H₄(O)C=N–N=C(CH₂Ph)COO](EtOH)(C₆H₅CH₂)₂Sn}₂ (3), were synthesized by reactions of 2-oxo-3-phenylpropionic acid salicyloylhydrazone with the corresponding diorganotin(IV) complex, respectively. All the complexes were characterized by IR, ¹H, ¹³C, ¹¹⁹Sn NMR spectra, elemental analysis, X-ray single crystal diffraction and TGA. For in vitro antitumor activities, complexes were evaluated by the MTT assay against three human cancer cell lines (NCI-H460, HepG2 and MCF7) and human cell line (HL7702). The results showed that 1 may be a better potential candidate for further chemical optimization and cancer therapy than 2 and 3. The interactions between the complexes and calf thymus DNA were studied; the interaction of 1 with calf thymus DNA was intercalation, 2 and 3 were intercalation and electrostatic binding.     

Organo‐Palladium(II)‐Verbindungen mit PdC4‐Koordination: Phenylethinyl‐ und Methylphenylethinylkomplexe

Tetrakis(p‐tolyl)oxalamidinato‐bis[acetylacetonatopalladium(II)] ([Pd₂(acac)₂(oxam)]) reacted with Li–C≡C–C₆H₅ in THF with formation of [Pd(C≡C–C₆H₅)₄Li₂(thf)₄] ( 1a ). Reaction of [Pd₂(acac)₂(oxam)] with a mixture of 6 equiv. Li–C≡C–C₆H₅ and 2 equiv. LiCH₃ resulted in the formation of [Pd(CH₃)(C≡C–C₆H₅)₃Li₂(thf)₄] ( 2 ), and the dimeric complex [Pd₂(CH₃)₄(C≡C–C₆H₅)₄Li₄(thf)₆] ( 3 ) was isolated upon reaction of [Pd₂(acac)₂(oxam)] with a mixture of 4 equiv. Li–C≡C–C₆H₅ and 4 equiv. LiCH₃. 1 – 3 are extremely reactive compounds, which were isolated as white needles in good yields (60–90%). They were fully characterized by IR, ¹H‐, ¹³C‐, ⁷Li‐NMR spectroscopy, and by X‐ray crystallography of single crystals. In these compounds Li ions are bonded to the two carbon atoms of the alkinyl ligand. 1a reacted with Pd(PPh₃)₄ in the presence of oxygen to form the already known complexes trans‐[Pd(C≡C–C₆H₅)₂(PPh₃)₂] and [Pd(η²‐O₂)(PPh₃)₂]. In addition, 1a is an active catalyst for the Heck coupling reaction, but less active in the catalytic Sonogashira reaction.     

Synthesis,Structure, and Reactivity of RuII Complexes with Trimethylsilylethinylamidinate Ligands

The mononuclear amidinate complexes [(η⁶‐cymene)‐RuCl( 1a )] ( 2 ) and [(η⁶‐C₆H₆)RuCl( 1b )] ( 3 ), with the trimethylsilyl‐ethinylamidinate ligands [Me₃SiC≡CC(N‐c‐C₆H₁₁)₂]^– ( 1a^– ) and[Me₃SiC≡CC(N‐i‐C₃H₇)₂]^– ( 1b^– ) were synthesized in high yields by salt metathesis. In addition, the related phosphane complexes[(η⁵‐C₅H₅)Ru(PPh₃)( 1b )] ( 4a ) [(η⁵‐C₅Me₅)Ru(PPh₃)( 1b )] ( 4b ), and [(η⁶‐C₆H₆)Ru(PPh₃)( 1b )](BF₄) ( 5 ‐BF₄) were prepared by ligand exchange reactions. Investigations on the removal of the trimethyl‐silyl group using [Bu₄N]F resulted in the isolation of [(η⁶‐C₆H₆)Ru(PPh₃){(N‐i‐C₃H₇)₂CC≡CH}](BF₄) ( 6 ‐BF₄) bearing a terminal alkynyl hydrogen atom, while 2 and 3 revealed to yield intricate reaction mixtures. Compounds 1a / b to 6 ‐BF₄ were characterized by multinuclear NMR (¹H, ¹³C, ³¹P) and IR spectroscopy and elemental analyses, including X‐ray diffraction analysis of 1b , 2 , and 3 .     

Zur oxidativen Addition von 1-Halogenalk-1-inen – Synthese und Struktur von Phenylalkinylpalladium-Komplexen

On the Oxidative Addition of 1-Halogenalk-1-ynes – Synthesis and Structure of Phenylalkynylpalladium Complexes [Pd(PPh₃)₄] ( 2 ) reacts with IC≡CPh and ClC≡CPh in the sense of an oxidative addition to give trans-[Pd(C≡CPh)X(PPh₃)₂] (X = I: 3 a , X = Cl: 3 b ). As side products trans-[PdX₂(PPh₃)₂] (X = I: 4 a , X = Cl: 4 b ; < 10%) and PhC≡C–C≡CPh ( 5 ; X = I: ca 30%, X = Cl: < 4%) are formed. 3 a and 3 b were characterized by NMR (¹H, ¹³C, ³¹P) and IR spectroscopies as well as by X-ray single-crystal structure analyses. In the crystals of 3 a and 3 b isolated molecules were found. The Pd–C≡C–Ph unit is linear in 3 a and approximately linear in 3 b [Pd–C≡C 174.2(6)°, C≡C–C 179,0(7)°].     

Transition‐Metal Complexes Based on the 1,3,5‐Triethynyl Benzene Linking Unit

The synthesis of a unique series of heteromultinuclear transition metal compounds is reported. Complexes 1‐I‐3‐Br‐5‐(FcC≡C)‐C₆H₃ ( 4 ), 1‐Br‐3‐(bpy‐C≡C)‐5‐(FcC≡C)‐C₆H₃ ( 6 ), 1,3‐(bpy‐C≡C)₂‐5‐(FcC≡C)‐C₆H₃ ( 7 ), 1‐(XC≡C)‐3‐(bpy‐C≡C)‐5‐(FcC≡C)‐C₆H₃ ( 8 , X = SiMe₃; 9 , X = H), 1‐(HC≡C)‐3‐[(CO)₃ClRe(bpy‐C≡C)]‐5‐(FcC≡C)‐C₆H₃ ( 11 ), 1‐[(Ph₃P)AuC≡C]‐3‐[(CO)₃ClRe(bpy‐C≡C)]‐5‐(FcC≡C)‐C₆H₃ ( 13 ), 1‐[(Ph₃P)AuC≡C]‐3‐(bpy‐C≡C)‐5‐(FcC≡C)‐C₆H₃ ( 14 ), [1‐[(Ph₃PAuC≡C]‐3‐[{[Ti](C≡CSiMe₃)₂}Cu(bpy‐C≡C)]‐5‐(FcC≡C)‐C₆H₃]PF₆ ( 16 ), and [1,3‐[(tBu₂bpy)₂Ru(bpy‐C≡C)]₂‐5‐(FcC≡C)‐C₆H₃](PF₆)₄ ( 18 ) (Fc = (η⁵‐C₅H₄)(η⁵‐C₅H₅)Fe, bpy = 2,2′‐bipyridiyl‐5‐yl, [Ti] = (η⁵‐C₅H₄SiMe₃)₂Ti) were prepared by using consecutive synthesis methodologies including metathesis, desilylation, dehydrohalogenation, and carbon–carbon cross‐coupling reactions. In these complexes the corresponding metal atoms are connected by carbon‐rich bridging units comprising 1,3‐diethynyl‐, 1,3,5‐triethynylbenzene and bipyridyl units. They were characterized by elemental analysis, IR and NMR spectroscopy, and partly by ESI‐TOF mass spectrometry., The structures of 4 and 11 in the solid state are reported. Both molecules are characterized by the central benzene core bridging the individual transition metal complex fragments. The corresponding acetylide entities are, as typical, found in a linear arrangement with representative M–C, C–C_C≡C and C≡C bond lengths.     

New Ga/N‐based Active Lewis Pairs,Trifunctional Ga–Ga Compounds,Reactions with Cyanamide and Dual Insertion of Isocyanate

Hydrogallation of Me₃Si–C≡C–NR'₂ with R₂Ga–H (R = tBu, CH₂tBu, iBu) yielded Ga/N‐based active Lewis pairs, R₂Ga–C(SiMe₃)=C(H)–NR'₂ ( 7 ). The Ga and N atoms adopt cis‐positions at the C=C bonds and show weak Ga–N interactions. tBu₂GaH and Me₃Si–C≡C–N(C₂H₄)₂NMe afforded under exposure of daylight the trifunctional digallium(II) compound [MeN(C₂H₄)₂N](H)C=C(SiMe₃)Ga(tBu)–Ga(tBu)C(SiMe₃)=C(H)[N(C₂H₄)₂NMe] ( 8 ), which results from elimination of isobutene and H₂ and Ga–Ga bond formation. 8 was selectively obtained from the ynamine and [tBu(H)Ga–Ga(H)tBu]₂[HGatBu₂]₂. 7a (R = tBu; NR'₂ = 2,6‐Me₂NC₅H₈) and H₈C₄N–C≡N afforded the adduct tBu₂Ga‐C(SiMe₃)=C(H)(2,6‐Me₂NC₅H₈) · N≡C–NC₄H₈ ( 11 ) with the nitrile bound to gallium. The analogous ALP with harder Al atoms yielded an adduct of the nitrile dimer or oligomers of the nitrile at room temperature. The reaction of 7a with Ph–N=C=O led to the insertion of two NCO groups into the Ga–C_vinyl bond to yield a GaOCNCN heterocycle with Ga bound to O and N atoms ( 12 ).     

Synthesis of 2‐ and 2,7‐Functionalized Pyrene Derivatives: An Application of Selective C?H Borylation

An efficient synthetic route to 2‐ and 2,7‐substituted pyrenes is described. The regiospecific direct C? H borylation of pyrene with an iridium‐based catalyst, prepared in situ by the reaction of [{Ir(μ‐OMe)cod}₂] (cod=1,5‐cyclooctadiene) with 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine, gives 2,7‐bis(Bpin)pyrene ( 1 ) and 2‐(Bpin)pyrene ( 2 , pin=OCMe₂CMe₂O). From 1 , by simple derivatization strategies, we synthesized 2,7‐bis(R)‐pyrenes with R=BF₃K ( 3 ), Br ( 4 ), OH ( 5 ), B(OH)₂ ( 6 ), and OTf ( 7 ). Using these nominally nucleophilic and electrophilic derivatives as coupling partners in Suzuki–Miyaura, Sonogashira, and Buchwald–Hartwig cross‐coupling reactions, we obtained 2,7‐bis(R)‐pyrenes with R=(4‐CO₂C₈H₁₇)C₆H₄ ( 8 ), Ph ( 9 ), C≡CPh ( 10 ), C≡C[{4‐B(Mes)₂}C₆H₄] ( 11 ), C≡CTMS ( 12 ), C≡C[(4‐NMe₂)C₆H₄] ( 14 ), C≡CH ( 15 ), N(Ph)[(4‐OMe)C₆H₄] ( 16 ), and R=OTf, R′=C≡CTMS ( 13 ). Lithiation of 4 , followed by reaction with CO₂, yielded pyrene‐2,7‐dicarboxylic acid ( 17 ), whilst borylation of 2‐tBu‐pyrene gave 2‐tBu‐7‐Bpin‐pyrene ( 18 ) selectively. By similar routes (including Negishi cross‐coupling reactions), monosubstituted 2‐R‐pyrenes with R=BF₃K ( 19 ), Br ( 20 ), OH ( 21 ), B(OH)₂ ( 22 ), [4‐B(Mes)₂]C₆H₄ ( 23 ), B(Mes)₂ ( 24 ), OTf ( 25 ), C≡CPh ( 26 ), C≡CTMS ( 27 ), (4‐CO₂Me)C₆H₄ ( 28 ), C≡CH ( 29 ), C₃H₆CO₂Me ( 30 ), OC₃H₆CO₂Me ( 31 ), C₃H₆CO₂H ( 32 ), OC₃H₆CO₂H ( 33 ), and O(CH₂)₁₂Br ( 34 ) were obtained from 2 . These derivatives are of synthetic and photophysical interest because they contain donor, acceptor, and conjugated substituents. The crystal structures of compounds 4 , 5 , 7 , 12 , 18 , 19 , 21 , 23 , 26 , and 28 – 31 have also been obtained from single‐crystal X‐ray diffraction data, revealing a diversity of packing modes, which are described in the Supporting Information. A detailed discussion of the structures of 1 and 2 , their polymorphs, solvates, and co‐crystals is reported separately.     

Synthese,Struktur und Eigenschaften der Komplexe [(Me2PhP)3Cl2Re≡N‐IrCl2(C5Me5)], [(Me2PhP)3Cl2Re≡N‐IrCl(COD)], [PPh4][O3Os≡N‐IrCl2(C5Me5)] und [PPh4][O3Os≡N‐IrCl(COD)] mit Nitridobrücken Re≡N‐Ir und Os≡N‐Ir

Synthesis and Crystal Structures of the Complexes [(Me₂PhP)₃Cl₂Re≡N‐IrCl₂(C₅Me₅)], [(Me₂PhP)₃Cl₂Re≡N‐IrCl(COD)], [PPh₄][O₃Os≡N‐IrCl₂(C₅Me₅)], and [PPh₄][O₃Os≡N‐IrCl(COD)] with Nitrido bridges Re≡N‐Ir and Os≡N‐Ir The heteronuclear complexes [(Me₂PhP)₃Cl₂Re≡N‐IrCl₂(C₅Me₅)] ( 1 ), [(Me₂PhP)₃Cl₂Re≡N‐IrCl(COD)] ( 2 ), [PPh₄][O₃Os≡N‐IrCl₂(C₅Me₅)] ( 3 ) and [PPh₄][O₃Os≡N‐IrCl(COD)] ( 4 ) were obtained by the reaction of the nitrido complexes [ReNCl₂(PMe₂Ph)₃] and [OsO₃N]^— with the iridium compounds [IrCl₂(C₅Me₅)]₂ and [IrCl(COD)]₂ in benzonitrile. 1 forms red crystals with the composition 1 ·C₆H₅CN in the monoclinic space group P2₁/c and a = 1264.7(2); b = 1945.3(2); c = 1835.4(1) pm, β = 90.35(1)°, Z = 4. The complex fragment [IrCl₂(C₅Me₅)] in the dinuclear complex is connected by an asymmetric nitrido bridge Re≡N‐Ir to the nitrido complex [ReNCl₂(PMe₂Ph)₃]. The nitrido bridge is characterized by a Re‐N‐Ir bond angle of 179.4(2)° and distances Re‐N = 170.9(4) pm and Ir‐N = 203.3(4) pm. 2 forms brownish red, triclinic crystals with the space group P1¯ and a = 1076.6(2), b = 1373.2(2), c = 1452.4(1) pm, α = 107.513(8), β = 101.843(9), γ = 110.04(1)°, Z = 2. The nitrido bridge to the complex fragment [IrCl(COD)] has a Re‐N‐Ir bond angle of 173, 8(4)° and distances Re‐N = 170, 4(8) pm and Ir‐N = 196, 2(8) pm. 3 crystallizes as monoclinic red crystals in the space group P2₁/n and a = 1449.9(2), b = 906.74(4), c = 2628.9(5) pm, β = 103.50(1)°, Z = 4. The nitrido bridge Os≡N‐Ir is slightly bent (Os‐N‐Ir = 165.0(3)°). The distances are Os‐N = 168.3(5) pm and Ir‐N = 201.9(5) pm. 4 forms dark brown, orthorhombic crystals with the space group P2₁2₁2₁ and a = 704.35(2), b = 1228.17(6), c = 3442.0(4) pm, Z = 4. The distances in the slightly bent nitrido bridge (Os‐N‐Ir = 161.8(4)°) are Os‐N = 169.3(7) pm und Ir‐N = 197.8(7) pm.     

Reactions of transition metal σ-acetylide complexes: IX. Preparation and properties of some cycloheptatrienylvinylidene complexes

Addition of [C₇H₇][PF₆] to iron, ruthenium or osmium alkynyl complexes has given eight cationic cycloheptatrienylvinylidene derivatives [M{C C(C₇H₇)R}(L)₂ (η-C₅H₅)][PF₆] (M = Fe, Ru or Os; R = Me, Pr, Ph or C₆F₅; L = PPh₃, L₂ = dppm or dppe; but not all combinations). With Fe(C₂Ph)(CO)₂(η-C₅H₅), only [Fe(CO)₂(thf)(η-C₅H₅)][PF₆] was obtained. Reactions of the new complexes are characterised by loss of the C₇H₇ group. The NMR spectra and FAB mass spectra are described in detail.     

Synthese und Struktur von (Me2PhP)3Cl2Re≡N–ReCl4(PMe2Ph), einem gemischtvalenten Zweikernkomplex mit einer Nitridobrücke zwischen ReV und ReIV

Synthesis and Structure of (Me₂PhP)₃Cl₂Re≡N–ReCl₄(PMe₂Ph), a Mixed Valent Dinuclear Complex with a Nitrido Bridge between Re^V and Re^IV The nitrido complex (Me₂PhP)₃Cl₂Re≡N–ReCl₄(PMe₂Ph) results from the reaction of ReNCl₂(PMe₂Ph)₃ with GeCl₄ in toluene. The mixed valent dinuclear complex is paramagnetic with μ_eff = 1.96 B. M. at 300 K. It crystallizes with one solvate molecule as red crystals (Me₂PhP)₃Cl₂Re≡N–ReCl₄(PMe₂Ph) · C₇H₈ with the space group P 1 and a = 1075.4(6), b = 1330.5(6), c = 1745.3(11) pm, α = 101.20(3), β = 105.88(3), γ = 94.23(3)°, Z = 2. In the dinuclear complex one molecule ReNCl₂(PMe₂Ph)₃ coordinates with its nitrido ligand to a fragment ReCl₄(PMe₂Ph). The resulting nitrido bridge is asymmetrical with distances Re–N of 170.6(6) and 205.5(6) pm, and a bond angle Re1–N–Re2 = 174.6(3)°.     

Synthesis of platinum acetylide complexes and their application in curing silicone rubber by hydrosilylation

Eight platinum acetylide complexes have been synthesized and characterized. The catalytic properties of these complexes in curing silicone rubber by hydrosilylation have been tested. Among the complexes tested, trans‐Pt(PPh₃)₂[―C≡CC(CH₃)₂OSi(CH₃)₃] ₂ (2), trans‐Pt(PPh₃)₂[―C≡CC(CH₃)₂OSi(CH₂CH₃)₃]₂ (3), trans‐Pt(PPh₃)₂[―C≡CC(CH₃)₂OSiPh(CH₃)₂]₂ (4), trans‐Pt(PPh₃)₂[―C≡C(C₆H₁₀)OSi(CH₃)₃]₂ (6), trans‐Pt(PPh₃)₂[―C≡C(C₆H₁₀)OSi(CH₂CH₃)₃]₂ (7), and trans‐Pt(PPh₃)₂[―C≡C(C₆H₁₀)OSiPh(CH₃)₂]₂ (8) exhibited sufficiently long pot‐lives (15 days) at room temperature and short silicone rubber curing times of 10–35 min at 100°C or 1–5 min at 120°C. Copyright © 2012 John Wiley & Sons, Ltd.     

Structural,Theoretical, and Spectroscopic Study of Mercury(II) Complexes of two New Unsymmetric Phosphorus Ylides

Abstract

The reaction of Ph₂PCH₂PPh₂ (dppm) with 4-methylphenacyl bromide and 2-(bromoacetyl)naphthalene in chloroform produce the new phosphonium salts [Ph₂PCH₂PPh₂CH₂C(O)C₆H₄Me]Br (1) and [Ph₂PCH₂PPh₂CH₂C(O)C₁₀H₇]Br (2). Further, by reaction of the monophosphonium salts of dppm with the strong base Et₃N the corresponding bidentate phosphorus ylides, Ph₂PCH₂P(Ph)₂ = C(H)C(O)C₆H₄Me (3) and Ph₂PCH₂P(Ph)₂ = C(H)C(O)C₁₀H₇ (4) were obtained. The reaction of these ligands with mercury(II) halides in dry methanol led to the formation of the mononuclear complexes {HgX ₂[(Ph₂PCH₂PPh₂C(H)C(O)C₆H₄Me)]} [X = Cl (5), Br (6), and I (7)] and {HgX ₂[(Ph₂PCH₂PPh₂C(H)C(O)C₁₀H₇)]} [X = Cl (8), Br (9), and I (10)]. Characterization of the obtained compounds was performed by elemental analysis, IR, ¹H, ³¹P, and ¹³C NMR spectra. The structure of compounds 3 and 10 are unequivocally determined by single crystal X-ray diffraction techniques. X-ray analysis of 10 reveals the presence of mononuclear complex containing Hg atom in a distorted tetrahedral environment. In all complexes, the title ylides are coordinated through the ylidic carbon and the phosphine phosphorus. Computational studies on ligand 4 and complexes 8, 9, and 10 at DFT (B3LYP) level of theory are also reported. It was shown that the formation of P,C-coordinated 1+1 complex 10 is energetically more favored than corresponding P,P-coordinated 1+2 product.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the following free supplemental files: Additional figures]     

Synthesis,structural, electrochemical,and spectroscopic studies of some (diimine)ruthenium nitrile complexes

The syntheses of cationic ruthenium(II) complexes [Ru(Me₂-bpy)(PPh₃)₂RR?][PF₆]_x {Me₂-bpy = 4,4?-dimethyl-2,2?-bipyridine, (3) R = Cl, R? = N≡CMe, x = 1, (4) R = Cl, R? = N≡CPh, x = 1, (5) R = R? = N≡CMe, x = 2} and [Ru(Me₂-bpy)(κ²-dppf)RR?][PF₆]_x {dppf = 1,1?-bis(diphenylphosphino)ferrocene, (6) R = Cl, R? = N≡CMe, x = 1, (7) R = Cl, R? = N≡CPh, x = 1, (8) R = R? = N≡CMe, x = 2} are reported, together with their structural confirmation by NMR (³¹P, ¹H) and IR spectroscopy and elemental analysis, and, in the case of trans-[Ru(Me₂-bpy)(PPh₃)₂(N≡CCH₃)Cl][PF₆] (3), by X-ray crystallography. Electronic absorption and emission spectra of the complexes reveal that all complexes except 4 and 6 are emissive in the range 370–400 nm with 8 exhibiting an emission in the blue. Cyclic voltammetry studies of 3–8 show reversible or quasi-reversible redox processes at ca. 1 V, assigned to the Ru(II/III) couple.     

Syntheses and Structures of trans-bis(Alkenylacetylide) Ruthenium Complexes

A series of ruthenium alkenylacetylide complexes trans-[Ru{C≡CC(=CH₂)R}Cl(dppe)₂] (R=Ph ( 1 a ), ^cC₄H₃S ( 1 b ), 4-MeS-C₆H₄ ( 1 c ), 3,3-dimethyl-2,3-dihydrobenzo[b]thiophene (DMBT) ( 1 d )) or trans-[Ru{C≡C-^cC₆H₉}Cl(dppe)₂] ( 1 e ) were allowed to react with the corresponding propargylic alcohol HC≡CC(Me)R(OH) (R=Ph ( A ), ^cC₄H₃S ( B ), 4-MeS-C₆H₄ ( C ), DMBT ( D ) or HC≡C-^cC₆H₁₀(OH) ( E ) in the presence of TlBF₄ and DBU to presumably give alkenylacetylide/allenylidene intermediates trans-[Ru{C≡CC(=CH₂)R}{C=C=C(Me)}(dppe)₂]PF₆ ([ 2 ]PF₆). These complexes were not isolated but deprotonated to give the isolable bis(alkenylacetylide) complexes trans-[Ru{C≡CC(=CH₂)R}₂(dppe)₂] (R=Ph ( 3 a ), ^cC₄H₃S ( 3 b ), 4-MeS-C₆H₄ ( 3 c ), DMBT ( 3 d )) and trans-[Ru{C≡C-^cC₆H₉}₂(dppe)₂] ( 3 e ). Analogous reactions of trans-[Ru(CH₃)₂(dmpe)₂], featuring the more electron-donating 1,2-bis(dimethylphosphino)ethane (dmpe) ancillary ligands, with the propargylic alcohols A or C and NH₄PF₆ in methanol allowed isolation of the intermediate mixed alkenylacetylide/allenylidene complexes trans-[Ru{C≡CC(=CH₂)R}{C=C=C(Me)}(dmpe)₂]PF₆ (R=Ph ([ 4 a ]PF₆), 4-MeS-C₆H₄ ([ 4 c ]PF₆). Deprotonation of [ 4 a ]PF₆ or [ 4 c ]PF₆ gave the symmetric bis(alkenylacetylide) complexes trans-[Ru{C≡CC(=CH₂)R}₂(dmpe)₂] (R=Ph ( 5 a ), 4-MeS-C₆H₄ ( 5 c )), the first of their kind containing the dmpe ancillary ligand sphere. Attempts to isolate bis(allenylidene) complexes [Ru{C=C=C(Me)R}₂(PP)₂]²⁺ (PP=dppe, dmpe) from treatment of the bis(alkenylacetylide) species 3 or 5 with HBF₄ ⋅ Et₂O were ultimately unsuccessful.     

Synthese und Struktur der Komplexe [(Me2PhP)3Cl2Re≡N‐RuCl2(C6H6)] und [(Me2PhP)3Cl2Re≡N‐RhCl(COD)]

Synthesis and Crystal Structure of the Complexes [(Me₂PhP)₃Cl₂Re≡N‐RuCl₂(C₆H₆)] and [(Me₂PhP)₃Cl₂Re≡N‐RhCl(COD)] The heteronuclear complex [(Me₂PhP)₃Cl₂Re≡N‐RuCl₂(C₆H₆)] ( 1 ) is obtained by the reaction of [ReNCl₂(PMe₂Ph)₃] with [RuCl₂(C₆H₆)]₂ in C₆H₅CN in form of red crystals with the composition 1 ·C₆H₅CN crystallizing in the monoclinic space group P2₁/c with a =1149.77(8), b = 3085.9(3), c = 1172.1(1) pm, β = 104.766(9)° and Z = 4. In the dinuclear complex the complex fragment [RuCl₂(C₆H₆)] is connected by an asymmetric nitrido bridge with the nitrido complex [ReNCl₂(PMe₂Ph)₃]. The nitrido bridge is characterised by a bond angle Re‐N‐Ru of 170.6(3)° and distances Re‐N = 170.2(5) and Ru‐N = 199.0(5) pm. The reaction of [ReNCl₂(PMe₂Ph)₃] with [RhCl(COD)]₂ in benzonitrile yields orange crystals of [(Me₂PhP)₃Cl₂Re≡N‐RhCl(COD)] ( 2 ) with the space group P2₁/c and a = 1522.3(2), b = 1274.85(4), c = 1921.2(2) pm, β = 106.759(7)° and Z = 4. The monovalent Rh atom exhibits a square planar coordination with the two π‐bonds of the cycloocta‐1, 5‐diene occupying cis positions. The distances in the almost linear nitrido bridge (Re‐N‐Rh = 174.8(4)°>) are Re‐N = 172.2(6) pm and Rh‐N = 195.6(6) pm.     

Diversification of ortho‐Fused Cycloocta‐2,5‐dien‐1‐one Cores and Eight‐ to Six‐Ring Conversion by σ Bond C−C Cleavage

Sequential treatment of 2‐C₆H₄Br(CHO) with LiC≡CR¹ (R¹=SiMe₃, tBu), nBuLi, CuBr?SMe₂ and HC≡CCHClR² [R²=Ph, 4‐CF₃Ph, 3‐CNPh, 4‐(MeO₂C)Ph] at ?50 °C leads to formation of an intermediate carbanion (Z)‐1,2‐C₆H₄{C_A(=O)C≡C_BR¹}{CH=CH(CH^?)R²} ( 4 ). Low temperatures (?50 °C) favour attack at C_B leading to kinetic formation of 6,8‐bicycles containing non‐classical C‐carbanion enolates ( 5 ). Higher temperatures (?10 °C to ambient) and electron‐deficient R² favour retro σ‐bond C?C cleavage regenerating 4 , which subsequently closes on C_A providing 6,6‐bicyclic alkoxides ( 6 ). Computational modelling (CBS‐QB3) indicated that both pathways are viable and of similar energies. Reaction of 6 with H⁺ gave 1,2‐dihydronaphthalen‐1‐ols, or under dehydrating conditions, 2‐aryl‐1‐alkynylnaphthlenes. Enolates 5 react in situ with: H₂O, D₂O, I₂, allylbromide, S₂Me₂, CO₂ and lead to the expected C ‐E derivatives (E=H, D, I, allyl, SMe, CO₂H) in 49–64 % yield directly from intermediate 5 . The parents (E=H; R¹=SiMe₃, tBu; R²=Ph) are versatile starting materials for NaBH₄ and Grignard C=O additions, desilylation (when R¹=SiMe) and oxime formation. The latter allows formation of 6,9‐bicyclics via Beckmann rearrangement. The 6,8‐ring iodides are suitable Suzuki precursors for Pd‐catalysed C?C coupling (81–87 %), whereas the carboxylic acids readily form amides under T3P® conditions (71–95 %).     

Polymerization of p‐diethynylbenzene and its derivatives with nickelocene acetylide catalysts containing different phosphine and alkynyl ligands

We developed a new series of single‐component air‐ and moisture‐stable catalysts for alkyne polymerization based on nickelocene complexes containing phosphine and alkynyl ligands. Chlorine, phosphine and alkynyl ligands exhibited great influence on the catalytic activity of the nickelocene complexes. Highly soluble polymers with fairly high molecular weight (M_w 23 400) were obtained in high yields (85%) in the homogeneous polymerization of p‐diethynylbenzene initiated with five nickelocene acetylides (π‐C₅H₅)LNi(C≡CR) (L = PPh₃, PBu₃; R = p‐C₆H₄C≡CH, C₆H₅, H) under mild conditions.