Five- and six-coordinate hydridorhodium(III) complexes containing metalated Schiff-bases as ligands

The reactions of either [RhCl(C₈H₁₄)₂]₂ (2) or [RhCl(C₂H₄)₂]₂ (3) with Schiff-bases 1a-d derived from 2-aminopyridine afford, in the presence of four equivalents of PiPr₃, the octahedral chloro(hydrido)rhodium(III) complexes [{(C₅H₄N)NC(C₆H₄R)}RhHCl(PiPr₃)₂] (4a-d) in which the metalated Schiff-base behaves as a chelating ligand. Treatment of 4a (RH) with NaI and CF₃SO₃Tl produce the corresponding derivatives [{(C₅H₄N)NC(C₆H₅)}RhHX(PiPr₃)₂] (5, 6) by salt metathesis. The triflato compound 6 reacts with nBu₄NF · xH₂O to give [{(C₅H₄N)NC(C₆H₅)}RhHF(PiPr₃)₂] (7). While attempts to eliminate HCl from 4a failed, the reaction of 4a with AgPF₆ generates the five-coordinate cationic complex [{(C₅H₄N)NC(C₆H₅)}RhH(PiPr₃)₂]PF₆ (8) which adds one equivalent of acetonitrile to give [{(C₅H₄N)NC(C₆H₅)}RhH(NCCH₃)(PiPr₃)₂]PF₆ (9). Treatment of 4a with either nBu₂Mg or LiAlH₄ affords the dihydridorhodium(III) compound [{(C₅H₄N)NC(C₆H₅)}RhH₂(PiPr₃)₂] (10) being also accessible from 8 and nBu₂Mg.     

Diazo complexes of osmium: preparation of binuclear derivatives with bis(aryldiazene) and bis(aryldiazenido) bridging ligands

Depending on experimental conditions and the nature of the phosphite, the reaction of OsH₂P₄ [P=P(OEt)₃ and PPh(OEt)₂] with bis(aryldiazonium) salts [N₂Ar-ArN₂](BF₄)₂ [Ar-Ar=4,4^′-C₆H₄-C₆H₄, 4,4^′-(2-CH₃)C₆H₃-C₆H₃(2-CH₃), 4,4^′-C₆H₄-CH₂-C₆H₄ and 1,5-C₁₀H₆] afford the cis and the trans binuclear [{OsHP₄}₂(μ-HNNAr-ArNNH)](BPh₄)₂1, 2 aryldiazene derivatives. These complexes 1, 2 further react with the mono(diazonium) (4-CH₃C₆H₄N₂)BF₄ salt to give the bis(aryldiazene) [{Os(4-CH₃C₆H₄NNH)P₄}₂(μ-HNNAr-ArNNH)](BPh₄)₄3, 4 derivatives. Binuclear bis(aryldiazenido) [{OsP₄}₂(μ-N₂Ar-ArN₂)](BPh₄)₂ (6) [P=P(OEt)₃; Ar-Ar=4,4^′-C₆H₄-C₆H₄, 4,4^′-C₆H₄-CH₂-C₆H₄] complexes were prepared by deprotonating with NEt₃ the nitrile-diazene [{Os(4-CH₃C₆H₄CN)P₄}₂(μ-HNNAr-ArNNH)](BPh₄)₄ (5) derivatives. The aryldiazenido compounds 6 react with HCl to give the new aryldiazene [{OsClP₄}₂(μ-HNNAr-ArNNH)](BPh₄)₂ (7) derivatives. The characterisation of the complexes by IR and ¹H, ³¹P, ¹⁵N NMR data is also discussed. The reaction of the hydride OsH₂(PPh₂OEt)₄ with mono(diazonium) salts was also studied and led exclusively to the mono(aryldiazene) [OsH(ArN NH)(PPh₂OEt)₄]BPh₄ (8) (Ar=C₆H₅, 4-CH₃C₆H₄) derivatives. Spectroscopic data (¹H, ³¹P, ¹⁵N NMR) on ¹⁵N-labelled derivatives suggest the presence of two isomers with the N-bonded and the π-bonded ArNNH ligand, respectively.     

On the identification of ionic species of neutral halogen dimers, monomers and pincer type palladacycles in solution by electrospray mass and tandem mass spectrometry

Electrospray (ESI) mass spectra analysis of acetonitrile solutions of a series of neutral chloro dimers, pincer type, and monomeric palladacycles has enabled the detection of several of their derived ionic species. The monometallic cationic complexes Pd[κ¹-C,κ¹-N,κ¹-S-C(CH₃S-2-C₆H₄)C(Cl)CH₂N(CH₃)₂]⁺ (1a) and [Pd[κ¹-C,κ¹-N,κ¹-S-C(CH₃S-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](CH₃CN)]⁺ (1b) and the bimetallic cationic complex [κ¹-C,κ¹-N,κ¹-S-C(CH₃S-2-C₆H₄)C(Cl)CH₂N(CH₃)₂]Pd-Cl-Pd[κ¹-C,κ¹-N,κ¹-S-C(CH₃S-2-C₆H₄)C(Cl)CH₂N(CH₃)₂]⁺ (1c) were detected from an acetonitrile solution of the pincer palladacycles Pd[κ¹-C,κ¹-N,κ¹-S-C(CH₃S-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](Cl) 1. For the dimeric compounds {Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](μ-Cl)}₂ (2, Y=H and 3, CF₃), highly electronically unsaturated palladacycles [Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂]⁺ (2d, 3d) and their mono and di-acetonitrile adducts, namely, [Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](CH₃CN)]⁺ (2e, 3e) and [Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](CH₃CN)₂]⁺ (2f and 3f) were detected together with the bimetallic complex [Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂]-Cl-Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N](CH₃)₂]⁺ (2a, 3a) and its acetonitrile adducts [κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](CH₃CN)Pd-Cl-Pd[ κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂]⁺ (2b, 3b) and [κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](CH₃CN)Pd-Cl-Pd[κ¹-C, κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂(CH₃CN)]⁺ (2c, 3c). The dimeric palladacycle {Pd[κ¹-C,κ¹-N-C(CH₃O-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](μ-Cl)}₂ (4) is unique as it behaves as a pincer type compound with the OCH₃ substituent acting as an intramolecular coordinating group which prevents acetonitrile full coordination, thus forming the cationic complexes [(C₆H₄(o-CH₃O)CC(Cl)CH₂N(CH₃)₂-κO,κC,κN)Pd]⁺ (4b), [(C₆H₄(o-CH₃O)CC(Cl)CH₂N(CH₃)₂- κO,κC,κN)Pd(CH₃CN)]⁺ (4c) and [(C₆H₄ (o-MeO)CC(Cl)CH₂N(CH₃)₂-κO, κC,κN)Pd-Cl-Pd(C₆H₄(o-CH₃O)CC(Cl)CH₂N(CH₃)₂-κO,κC,κN)]⁺ (4a). ESI-MS spectra analysis of acetonitrile solutions of the monomeric palladacycles Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](Cl)(Py) (5, Y=H and 6, Y=CF₃) allows the detection of some of the same species observed in the spectra of the dimeric palladacycles, i.e., monometallic cationic 2d-3d, 2e-3e and {Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](Py)}⁺ (5a, 6a) and {Pd[κ¹-C,κ¹-N-C(Y-2-C₆H₄)C(Cl)CH₂N(CH₃)₂](CH₃CN)(Py)}⁺ (5b, 6b) and the bimetallic 2a, 3a, 2b, 3b, 2c and 3c. In all cationic complexes detected by ESI-MS, the cyclometallated moiety was intact indicating the high stability of the four or six electron anionic chelate ligands. The anionic (chloride) or neutral (pyridine) ligands are, however, easily replaced by the acetonitrile solvent.     

Versatility of pyridine-2-methanol as a chelating ligand toward a manganese ion: synthesis and X-ray structural analysis on some manganese-pyridine-2-methanol derivatives

A systematic synthesis and X-ray structural analysis have been made for several manganese derivatives with pyridine-2-methanol as a chelating ligand; neutral Mn(C₅NH₄-2-CH₂OH)₂(C₆F₅CO₂)₂ (1), trans-[Mn(C₅H₄N-2-CH₂-OH)₂{C₆F₄-1,4-(CO₂)₂}]_∞ (2), cis-[Mn(C₅H₄N-2-CH₂-OH)₂{C₆F₄-1,3-(CO₂)₂}]_∞ (3), {Mn(C₅H₄N-2-CH₂-OH)₂(4,4^′-bipyridine)(ClO₄)}_∞ (4), and Mn(C₅H₄N-2-CH₂-OH)₃(ClO₄)₂(4,4-azopiridine) (pyridine-2-methanol) (5) are our results. 1 and 5 are monomers, while 2-4 are polymers. An oxidation state of the manganese ion in 1, 2, 3, and 5 is 2⁺, while that of 4 is suggested to be 3⁺. The magnetic data of 4 down to 2 K are measured. The length of the linker ligand has been suggested to afford a crucial effect on the dimensionality of the product.     

Analysis of the main structural trends for biscyclometalated dinuclear rhodium compounds of general formula Rh2(O2CR)2(PC)2 · 2H2O

A new series of biscyclometalated dinuclear rhodium (II) compounds with the general formula Rh₂(O₂CR)₂(PC)₂ · 2H₂O, being PC = (C₆H₄)P(C₆H₅)₂, R = CH₃ (1 · 2H₂O), PC = [(p-CH₃ OC₆H₃)P(p-CH₃ OC₆H₄)₂], R = CF₃ (2 · 2H₂O), PC = (C₆H₄)P[CH(CH₃)₂]₂, R = CH₃ (3 · 2H₂O) and PC = (C₆H₄)P(C₆H₅)₂, R = C₆F₅ (4 · 2H₂O) has been obtained. The crystal structures for these compounds have been determined by X-ray diffraction and the main structural trends, bond lengths, bond angles and torsion angles have been analyzed, and have also been compared with the structural parameters for different analogous complexes described previously in the literature.     

New palladacyclopentadiene complexes containing an N,P-donor setting. Crystal structure of [Pd{C4(COOMe)4}(o-Ph2PC6H4CHNPr)]

The synthesis of palladacyclopentadiene derivatives with the mixed-donor bidentate ligands o-Ph₂PC₆H₄CHNR (N^∧P) has been achieved. The new complexes of general formula [Pd{C₄(COOMe)₄}(o-Ph₂PC₆H₄CHNR)] [R=Me (1), Et (2), ⁱPr (3), ^tBu (4), NHMe (5)] have been prepared by reaction between the precursor [Pd{C₄(COOMe)₄}]_n and the corresponding iminophosphine. The polymer complex [Pd{C₄(COOMe)₄}]_n also reacts with pyridazine (C₄H₄N₂) to give the insoluble dinuclear complex [Pd{C₄(COOMe)₄}(μ-C₄H₄N₂)]₂ (6), which has been successfully employed as precursor in the synthesis of pyridazine-based palladacyclopentadiene complexes. The reaction of 6 with tertiary phosphines yielded complexes containing an N,P-donor setting of formula [Pd{C₄(COOMe)₄}(C₄H₄N₂)(L)] (L=PPh₃ (7), PPh₂Me (8), P(p-MeOC₆H₄)₃ (9), P(p-FC₆H₄)₃ (10)). The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, ¹H, ¹⁹F and ³¹P NMR). The molecular structure of complex 3 has been determined by a single-crystal diffraction study, showing that the iminophosphine acts as chelating ligand with coordination around the palladium atom slightly distorted from the square-planar geometry.     

Strong 1,4 P-O intramolecular interactions as a source of conformational preferences in α-stabilised phosphorus ylides. Part 2: metallic complexes

The complexes cis-[PdCl₂{η²-[C(H)PH₃]₂CO}] (2) in two different stereochemical arrangements (cisoid-cisoid, 2cc; cisoid-transoid, 2ct) have been studied by DFT methods at the B3LYP level. The (2cc) structure is energetically more stable than the (2ct), being the main responsible of the energy difference between the two complexes the energetic gap between the cc and ct isomers of the free bis-ylide ligand [H₃PC(H)-C(O)-C(H)PH₃] (1). In (1) these differences arise from the presence of 1,4-intramolecular interactions between the phosphorus atoms and the carbonyl oxygen. That is, the conformational preferences observed in (1) due to the establishment of 1,4-P?O interactions are directly transferred to the metallic complexes (2) in such a way that the most stable structure for the free ligand gives the most stable complex. In the absence of the carbonyl group (e.g. [H₃PC(H)-C(CH₂)-C(H)PH₃] (3) or [H₃PC(H)-CH₂-C(H)PH₃] (5)) all isomers of a given bis-ylide (cc, ct and tt) become isoenergetic. The absence of discrimination in the free bis-ylides (3) and (5) gives isoenergetic cc and ct structures for the corresponding complexes cis-[PdCl₂{η²-[C(H)PH₃]₂CCH₂}] (4), cis-[PdCl₂{η²-[C(H)PH₃]₂CH₂}] (6) and [CpNi{η²-[C(H)PH₃]₂CH₂}] (7), as stated by NMR spectroscopy for (7). The influence of other factors (change of the heteroatom at C_β, change of the P substituents) in the energy of the different isomers of the bis-ylides and in the energy of the corresponding complexes has also been studied and discussed.     

Reactivity of platina-β-diketones towards chelating nitrogen and sulfur donors: formation of acyl(hydrido)platinum(IV) and acyl(chloro)platinum(II) complexes

The platina-β-diketone [Pt₂{(COMe)₂H}₂(μ-Cl)₂] (1) was found to react with chelating N,N-ligands 2(R^′NCR)C₅H₄N (R/R^′=Ph/OH, H/Ph, Me/Ph) to form acyl(hydrido)platinum(IV) complexes [Pt(COMe)₂Cl(H){2-(R^′NCR)C₅H₄N}] (R/R^′=Ph/OH 2a; H/Ph 2b; Me/Ph (2c)). Reactions of complex 1 with chelating S,S- and N,S-donors (RS-CH₂-CH₂-SR, 2-(RSCH₂)C₅H₄N, R=Et, Ph, t-Bu) afforded acyl(chloro)platinum(II) complexes [Pt(COMe)Cl(RSCH₂CH₂SR)] (R=Et, 3a; Ph, 3b; t-Bu, 3c) and [Pt(COMe)Cl{2-(RSCH₂)C₅H₄N}] (R=Et, 4a; Ph, 4b; t-Bu, 4c), respectively. All complexes were fully characterized by microanalysis, IR and NMR (¹H, ¹³C) spectroscopy. Furthermore, molecular structures of complexes 3b and 4b were determined by single-crystal X-ray diffraction analyses revealing close to square-planar configuration. In complex 4b the acetyl ligand is trans to pyridine N atom (configuration index SP-4-2). The reactions are discussed in terms of consecutive oxidative addition and reductive elimination reactions.     

Pyridine and phosphine reactions with [CPh3][B(C6F5)4]

Trityl borate salts [4-RPyCPh₃][B(C₆F₅)₄] (R = H 1, ^tBu 2, Et 3, NMe₂4) and [R₃PCPh₃][B(C₆F₅)₄] (R = Me 5, ⁿBu 6, Ph[1] 7, p-MeC₆H₄8) are readily prepared via equimolar reaction of the appropriate pyridine or phosphine and trityl borate [CPh₃][B(C₆F₅)₄]. The analogous reactions of PⁱPr₃ affords the product [(p-ⁱPr₃P-C₆H₄)Ph₂CH][B(C₆F₅)₄] (9) while the corresponding reactions of Cy₃P and ^tBu₃P gave the cyclohexadienyl derivatives [(p-R₃PC₆H₅)CPh₂][B(C₆F₅)₄] (R = Cy 10, ^tBu 11). X-ray structures of 5 and 9 are reported.     

Investigation on the coordination modes: Syntheses, characterization and crystal structures of diorganotin (IV) dichloride with 4(5)-imidazoledithiocarboxylic acid

A series of diorganotin (IV) complexes of the types of R₂SnCl(SSCC₃H₃N₂) (R = CH₃1, ⁿBu 2, C₆H₅3 and C₆H₅CH₂4), R₂Sn(SSCC₃H₃N₂)₂ (R = CH₃5, ⁿBu 6, C₆H₅7 and C₆H₅CH₂8) and R₂Sn(SSCC₃H₂N₂) (R = CH₃9, ⁿBu 10, C₆H₅11 and C₆H₅CH₂12) have been obtained by reactions of 4(5)-imidazoledithiocarboxylic acid with diorganotin (IV) dichlorides in the presence of sodium ethoxide. All complexes are characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectra analyses. Also, the complexes 1, 7 and 9 are characterized by X-ray crystallography diffraction analyses, which reveal that the complex 1 is monomeric structure with five-coordinate tin (IV) atom, the complex 7 is monomeric structure with six-coordinate tin (IV) atom and the complex 9 is one-dimensional chain with five-coordinate tin (IV) atom.     

2-Pyridylmetallocenes: Part I. Electrophilic halogenation of 2-pyridylferrocene. Molecular structures of 2-pyridylferrocene and its α-brominated and -fluorinated derivatives. Synthesis of 2-pyridylruthenocene and 2-pyridylcymantrene

A new high-yield synthesis of 2-pyridylferrocene (1) without formation of the 1,1′-disubstituted product has been developed. Also the corresponding ruthenocene and cymantrene derivatives [C₅H₄(2-C₅H₄N)]ML_n (ML_n = Ru(C₅H₅) (2), Mn(CO)₃ (3)) were prepared and fully characterized. Ortho-lithiation of 1 followed by electrophilic halogenation yielded [C₅H₃X(2-C₅H₄N)]Fe(C₅H₅) [X = F (4), Cl (5), Br (6), I (7)], with 4 only being the second reported and first fully characterized fluoroferrocene. The molecular structures of 1, 4 and 6 have been determined by X-ray crystallography.     

Ru2(CO)4(OOCR)2L2 sawhorse-type complexes containing axial 5-(4-pyridyl)-10,15,20-triphenylporphyrin ligands

The thermal reaction of Ru₃(CO)₁₂ with various carboxylic acids (benzoic, 4-hydroxyphenylacetic, ferrocenic, stearic, oleic, 4-(octadecyloxy)benzoic) in refluxing tetrahydrofuran, followed by addition of 5-(4-pyridyl)-10,15,20-triphenylporphyrin (L), gives the dinuclear complexes Ru₂(CO)₄(OOCR)₂L₂ (1: R = -C₆H₅, 2: R = -CH₂-p-C₆H₄OH, 3: R = -C₅H₄FeC₅H₅, 4: R = -(CH₂)₁₆CH₃, 5: R = -(CH₂)₇CHCH(CH₂)₇CH₃, 6: R = -p-C₆H₄O(CH₂)₁₇CH₃). Complexes 1-6 were characterised by IR, NMR, and ESI-MS as well as by elemental analysis. The UV-Vis spectra show the Soret band centred at 417 nm and the Q bands at 515, 550, 590 and 645 nm, respectively.     

Syntheses and structures of vinyl and aryl derivatives of carbonyl halide iron complexes

cis,trans-Fe(CO)₂(PMe₃)₂(p-Y-C₆H₄)X [X=Br, Y=H (4a), MeO (4b), Cl (4c), F (4d), Me (4e); X=I, Y=H (5); X=Cl, Y=H (6)] and cis,trans-Fe(CO)₂(PMe₃)₂(σ-CHCH₂)X [X=Br (7); X=I (8); X=Cl (9)] are prepared by reacting dihalide complexes cis,trans,cis- Fe(CO)₂(PMe₃)₂X₂ [X=Br (1), X=I (2), X=Cl (3)] with Grignard reagents p-Y-C₆H₄-MgBr (Y=H, OMe, Cl, F, Me) or CH₂CH-MgBr and with lithium reagents PhLi, CH₂CH-Li. With both reagents, the reaction proceeds following two parallel pathways: one is the metallation reaction which yields alkyl derivatives, the other affords 17 electron complexes [Fe(CO)₂(PMe₃)₂X] via monoelectron reductive elimination. The influence of the halides and organometallic reagents on the yield of the metallation reaction is discussed. The solution structure of the complexes is assigned on the basis of IR and ¹H, ¹³C, ¹⁹F, ³¹P NMR spectra. The solid state structure of complexes 4a, 5 and 6 is determined by single crystal X-ray diffractometric methods.     

Palladium(II), platinum(II), ruthenium(II) and mercury(II) complexes of potentially tridentate Schiff base ligands of (E, N, O) type (E = S, Se, Te): Synthesis, crystal structures and applications in Heck and Suzuki coupling reactions

Schiff bases of 2-hydroxybenzophenone (HBP) (C₆H₅)(2-HOC₆H₄)CN(CH₂)_nEAr (L1/L2: E = S, Ar = Ph, n = 2/3; L3/L4: E = Se, Ar = Ph, n = 2/3; L5/L6: E = Te, Ar = 4-MeOC₆H₄, n = 2/3) and their complexes [PdCl(L-H)] (L = L1−L6; 1, 2, 3, 5, 7, 11), [PtCl(L3-H/L5-H)] (4/8), [PtCl₂(L4/L6)₂] (6/12), [(p-cymene)RuCl(L5/L6)]Cl (9/13) and [HgBr₂(L5/L6)₂] (10/14) have been synthesized and characterized by proton, carbon-13, selenium-77 and tellurium-125 NMR, IR and mass spectra. Single crystal structures of L1, 1, 3, 4, 5 and 7 were solved. The Pd-E bond distances (Å): 2.2563(6) (E = S), 2.3575(6)−2.392(2) (E = Se); 2.5117(5)−2.5198(5) (E = Te) are near the lower end of the bond length range known for them. The Pt-Se bond length, 2.3470(8) Å, is also closer to the short values reported so far. The Heck and Suzuki reaction were carried out using complexes 1, 3, 5 and 7 as catalysts under aerobic condition. The percentage yields for trans product in Heck reaction were found upto 85%.     

The influence of hydrogen bonding on the rate of thiolate alkylation in tripod-zinc thiolate complexes

A series of new thioimidazolylborate zinc thiolate complexes Tti^xylZnSR (2)-(5) (where R = C₆H₄-o-OH, C₆H₄-o-CH₂OH, C₆H₄-o-NH₂, and C₆H₄-p-OH, respectively) have been synthesized and characterized as structural and functional models of the active site of the Ada repair protein. Structural determination of complexes 2-4 reveals intramolecular N/O-H?S hydrogen-bonding interactions. The influence of these hydrogen bonding interactions on the methylation of the thiolate ligands is evident from the fact that the rate of methylation for these complexes is reduced ca. 2 orders of magnitude compared to that found in the case of the non-hydrogen bonding-containing complex, Tti^xylZnSC₆H₅ (1).     

Syntheses and structural analyses of chiral rhenium containing amines of the formula (η-C5H5)Re(NO)(PPh3)((CH2)nNRR′) (n = 0, 1)

The reaction of the racemic chiral methyl complex (η⁵-C₅H₅)Re(NO)(PPh₃)(CH₃) (1) with CF₃SO₃H and then NH₂CH₂C₆H₅ gives [(η⁵-C₅H₅)Re(NO)(PPh₃)(NH₂CH₂C₆H₅)]⁺ ([4a-H]⁺; 73%), and deprotonation with t-BuOK affords the amido complex (η⁵-C₅H₅)Re(NO)(PPh₃)(NHCH₂C₆H₅) (76%). Reactions of 1 with Ph₃C⁺ X⁻ and then primary or secondary amines give [(η⁵-C₅H₅)Re(NO)(PPh₃)(CH₂NHRR′)]⁺ X⁻ ([6-H]⁺ X⁻; R/R′/X = a, H/NH₂CH₂C₆H₅/BF₄; a′, H/NH₂CH₂C₆H₅/PF₆; b, H/NH₂CH₂(CH₂)₂CH₃/PF₆; c, H/(S)-NH₂CH(CH₃)C₆H₅/BF₄); d, CH₂CH₃/CH₂CH₃/PF₆; e, CH₂(CH₂)₂CH₃/CH₂(CH₂)₂CH₃/PF₆; f, CH₂C₆H₅/CH₂C₆H₅/PF₆; g, -CH₂(CH₂)₂CH₂-/PF₆; h, -CH₂(CH₂)₃CH₂-/PF₆; i, CH₃/CH₂CH₂OH/PF₆ (62-99%). Deprotonations with t-BuOK afford the amines (η⁵-C₅H₅)Re(NO)(PPh₃)(CH₂NRR′) (6a-i; 99-40%), which are more stable and isolated in analytically pure form when R ≠ H. Enantiopure 1 is used to prepare (R_ReS_C)-[6c-H]⁺, (R_ReS_C)-6c, (S)-[6g-H]⁺, and (S)-6g. The crystal structures of [4a-H]⁺, a previously prepared NH₂CH₂Si(CH₃)₃ analog, [6a′,d,f,h-H]⁺, (R_ReS_C)-6c, and 6f are determined and analyzed in detail, particularly with respect to cation/anion hydrogen bonding and conformation. In contrast to analogous rhenium containing phosphines, 6a-i show poor activities in reactions that are catalyzed by organic amines.     

Phosphorus-carbon bond formation via reactions of triphenylphosphine with acetylene and pentamethylcyclopentadienyl coordinated to iridium(III)

Phosphorus-carbon bond is formed via: (i) the apparent HCCH insertion into Ir-P bond to produce Ir-CHCH-PPh₃ group and (ii) the activation of the ring-methyl group of the coordinated Cp^* (C₅Me₅ ⁻) to produce Ir(η⁵-C₅Me₄CH₂-PPh₃) group from reactions of iridium(III)-Cp^* complexes, [Cp^*IrL₃]ⁿ⁺ (n=1, 2); Cp^*=C₅Me₅ ⁻; L₃=Cl(PPh₃)₂ (3), (CH₃CN)₃ (5). The following new P-C bond containing iridium(III) complexes have been prepared: [Cp^*Ir(-CHCH-PPh₃)Cl(PPh₃)]⁺ (4) from 3 with HCCH; [Ir(η⁵-C₅Me₄CH₂-PPh₃)(H)(PPh₃)₂]²⁺ (6) from 5 with PPh₃; [Cp^*Ir(-CHCH-PPh₃)₂(PPh₃)]²⁺ (7) from 5 with HCCH and PPh₃; [Ir(η⁵-C₅Me₄CH₂-PPh₃)(-CHCH-PPh₃)Cl(PPh₃)]²⁺ (8) from [Ir(η⁵-C₅Me₄CH₂-PPh₃)(Cl)(PPh₃)₂]²⁺ (6-Cl) with HCCH; [Ir(η⁵-C₅Me₃(1,3-CH₂-PPh₃)₂(H)(PPh₃)₂)]³⁺ (10) from [Ir(η⁵-C₅Me₄CH₂-PPh₃)(NCCH₃)₂(PPh₃)]³⁺ (9) with PPh₃; [Ir(η⁵-C₅Me₄CH₂-PPh₃)(-CHCH-PPh₃)₂(PPh₃)]³⁺ (11) from 9 with HCCH and PPh₃.     

Phosphane- and phosphite-silver(I) phenolates: Synthesis, characterization and their use as CVD precursors

The silver(I) salts [AgOR] (3a, R = C₉H₆N; 3b, R = C₆H₄-2-CHO, 3c, R = C₆H₄-2-Cl; 3d, R = C₆H₄-2-CN; 3e, R = C₆H₄-2-NO₂) are accessible by the stoichiometric reaction of [AgNO₃] (1) with HOR (2a, R = C₉H₆N; 2b, R = C₆H₄-2-CHO; 2c, R = C₆H₄-2-Cl; 2d, R = C₆H₄-2-CN; 2e, R = C₆H₄-2-NO₂) in presence of NEt₃. Treatment of 3a-3e with PⁿBu₃ (4), P(OMe)₃ (5a) or P(OCH₂CF₃)₃ (5b) in the ratios of 1:1 and 1:2, respectively, produced complexes [L_mAgOR] (L = PⁿBu₃, m = 1: 6a, R = C₉H₆N; 6b, R = C₆H₄-2-CHO; 6c, R = C₆H₄-2-Cl; 6d, R = C₆H₄-2-CN; 6e, R = C₆H₄-2-NO₂. m = 2: 7a, R = C₉H₄; 7b, R = C₆H₄-2-CHO; 7c, R = C₆H₄-2-Cl; 7d, R = C₆H₄-2-CN; 7e, R = C₆H₄-2-NO₂. L = P(OMe)₃, m = 1: 8a, R = C₆H₄-2-CHO; 8b, R = C₆H₄-2-NO₂. m = 2: 9, R = C₆H₄-2-NO₂. L = P(OCH₂CF₃)₃, m = 1: 10, R = C₆H₄-2-NO₂). Based on TGA, temperature-programmed and in situ molecular beam mass spectrometry metal-organic 7e was applied as CVD precursor in the deposition of silver onto glass substrates. The resulting silver films were characterized by XRD. The SEM image of a film grown from 7e at 350 °C showed a homogeneous surface with grain sizes of 40 nm. The molecular structures of 8b and 10 in the solid state were determined. They are isostructural and are cubane-like structured. Low-temperature ³¹P{¹H} NMR studies showed that the title complexes are dynamic in solution and exchange at room temperature their ligands.     

Syntheses, characterizations, and olefin polymerizations of methylene-bridged 1,3-dimethylcyclopentadienyl/indenyl and 1,3-dimethylcyclopentadienyl/tetrahydroindenyl zirconium complexes

A cyclopentadiene compound having methyl substituents on 1,3-positions, 1,3-Me₂-2-CH₂(OTHP)-C₅H₃ (3) is prepared from 2-bromo-3-methyl-2-cyclopenten-1-one ethylene ketal (1) in 48% overall yield. Addition of 2.5 equivalents of indenyllithium to 3 affords a methylene bridged 1,3-dimethylcyclopentadienyl indenyl compound, CH₂(1,3-Me₂C₅H₃)(C₉H₇) (5) in 72% yield. Reaction of dilithium salt of 5 with ZrCl₂(NMe₂)₂ (DME) furnishes an ansa-zirconocene complex [CH₂(1,3-Me₂C₅H₂)(C₉H₆)]Zr(NMe₂)₂ (6), which is transformed cleanly to the dichloride complex, [CH₂(1,3-Me₂C₅H₂)(C₉H₆)]ZrCl₂ (7), by treatment of Me₃SiCl. Hydrogenation of 7 over PtO₂ gives a tetrahydroindenyl complex [CH₂(1,3-Me₂C₅H₂)(C₉H₁₀)]ZrCl₂ (8). Reaction of the dilithium salt of 5 with Ti(NMe₂)₂Cl₂ does not provide the desired ansa-titanocene complex, but a dinuclear complex [(1,3-Me₂C₅H₂)Ti(NMe₂)₂Cl]-CH₂-[(C₉H₆)Ti(NMe₂)Cl] (9) is obtained. The solid structures of 6 and 9 were determined by X-ray crystallography. The ethylene and ethylene/norbornene (co)polymerizations were studied with 7/MAO and 8/MAO.     

Reactions of rhodium(II) and iridium(III) complexes bearing a P,O-coordination with tetracyanoethylene in the presence of KPF6

Reactions of Cp*M(MDMPP-P,O)Cl (1a: M=Rh, 1b: M=Ir; MDMPP-P,O=PPh₂(2-O-6-MeOC₆H₃)) with tetracyanoethylene (tcne) in the presence of KPF₆ gave Cp*MCl[PPh₂{2-O-3-(C(CN)₂CH(CN)₂)-6-MeOC₆H₂}] (2), [{Cp*MPPh₂{2-O-3-(C(CN)C(CN)₂)-6-MeOC₆H₂}}₂(CN)](PF₆) (3), [{Cp*IrPPh₂{2-O-3-(C(CN)C(CN)₂)-6-MeOC₆H₂}}(CN){Cp*Ir(MDMPP-P,O)}](PF₆) (4b) and [{Cp*Ir(MDMPP-P,O)}₂(CN)](PF₆) (5b), depending on the reaction conditions. Reaction of 2 with KPF₆ or AgOTf in the absence and presence of xylyl isocyanide (XylNC) gave 3 or [Cp*MCl{PPh₂(2-O-3-(C(CN)₂-CH(CN)₂)-6-MeOC₆H₂)}(XylNC)](OTf) (6). The structure of 3a (M=Rh) was confirmed by X-ray crystal analysis.