Aerosol-assisted chemical vapour deposition (AACVD) of silver films from triorganophosphine adducts of silver carboxylates, including the structure of [Ag(O2CC3F7)(PPh3)2]

Silver carboxylates [Ag(O₂CR): R=Me, ^tBu, 2,4,6-Me₃C₆H₂], fluorocarboxlyates [Ag(O₂CR_f): R_f=C₃F₇, C₆F₁₃, C₇F₁₅] and their phosphine adducts [Ag(O₂CR)·nPR₃′: R=Me, ^tBu, 2,4,6-Me₃C₆H₂, R′=Me, Ph, n=2; R=Me, R′=Me, n=3; Ag(O₂CR_f).2PPh₃, R_f=C₃F₇, C₆F₁₃, C₇F₁₅] have been synthesised, characterised spectroscopically and used as precursors in the aerosol-assisted chemical vapour deposition of silver films. All the phosphine adducts produced films, though in general PMe₃ adducts, proved more successful than PPh₃ analogues. The fluoro-carboxylates and their PPh₃ adducts all generated silver films, though the growth rate for the adducts was lower. All these latter films showed carbon impurities while fluorine was also evident in most cases. The X-ray structure of AgO₂CC₃F₇·2PPh₃ is also reported.     

Silver(I) derivatives with new functionalised acylpyrazolonates

Silver(I) acylpyrazolonate derivatives of formula [Ag(Q)(R₃P)]₂ and [Ag(Q)(R₃P)₂], (QH=1-phenyl-3-methyl-4-R′(CO)-pyrazol-5-one; Q^OH, R′=furane; Q^SH, R′=thiophene; R=Ph, Cy, o-tol), have been synthesised and characterised, both in the solid state and in solution. The derivatives [Ag(Q)(R₃P)]₂ contain dinuclear AgO₂NP units with the acylpyrazolonate coordinating in a bridging O,O′-Q-N fashion. The [Ag(Q)(R₃P)₂] are tetrahedral species, with the distortion from ideal geometry increasing with the bulk of the phosphine. The [Ag(Q)(R₃P)₂] derivatives are fluxional in chloroform solution when R₃P is sterically hindered (R=Cy or o-tol), dissociating partially to the [Ag(Q)(R₃P)] fragment and free R₃P. [Ag(Q^S)(Ph₃P)]₂ reacts with 1-methyl-2-mercaptoimidazole (Hmimt) affording the compound [Ag(Hmimt)(Ph₃P)(Q^S)] and [Ag(Q^O)(Ph₃P)]₂ reacts with 1-methyl-imidazole (Meim) affording the compound [Ag(Meim)(Ph₃P)(Q^O)], whereas [Ag(Q^S)(Ph₃P)]₂ reacts with 1,10-phenanthroline (phen), affording the compound [Ag(phen)(Ph₃P)](Q^S). Finally [Ag(Q^S)(Ph₃P)₂] reacts with phen producing the ionic species [Ag(phen)(Ph₃P)₂](Q^S).     

Syntheses and characterizations of six hydrogen-bonded silver(I) complexes from assembly of silver(I) nitrate and aminobenzoic acid

Six hydrogen-bonded silver(I) complexes, Ag(4-abaH)₂(NO₃) (1), [Ag(4-abaH)₂(NO₃)]_n (2), {[Ag(4-aba)(4-abaH)] · H₂O}_n (3), {[Ag(4,4^′-bipy)(H₂O)](4-aba)_0.5(NO₃)_0.5 · (H₂O)_0.5}_n (4), [Ag[(3-abaH_0.5)₂] (5), and {[Ag(3-aba)] · H₂O}_n (6) (4-abaH=4-aminobenzoic acid, 3-abaH=3-aminobenzoic acid), have been synthesized and characterized by single-crystal X-ray diffraction analyses. In 1, 4-abaH serves as a monodentate ligand coordinating to Ag(I) through its nitrogen atom, while uncoordinated carboxylic group links (4-abaH)-Ag-(4-abaH) into a one-dimensional metallic carboxylic synthon. 2 may be regarded as an extension of 1 into a two-dimensional carboxylic synthon through NO₃ ⁻ bridging two adjacent Ag(I) centers. In 3, 4-abaH in a monodentate mode and 4-aba in a μ-N,O bridging mode link three-coordinated Ag(I) to form a one-dimensional swallow-like chain, which is further extended into a two-dimensional layer structure through inter-chain hydrogen bonding interactions. The alternating Ag(I) and 4,4^′-bipy in 4 give rise to a slightly distorted linear chain, which is further extended into a two-dimensional layer through the completely overlapping and off-set stacking interactions. The hydrogen bonds involving in weakly coordinated aqueous molecules and 4-aba further extend it into a three-dimensional framework. In 5, the inter-molecular hydrogen bonding and π-π stacking interactions extend Ag[(3-abaH_0.5)₂] into a two-dimensional supramolecular architecture. In 6, 3-aba in a μ₃-N,O,O^′ coordination mode links three three-coordinated Ag(I) into a two-dimensional network. Uncoordinated aqueous molecules and the adjacent 3-aba oxygen atoms form intermolecular hydrogen bonds.     

3D coordination polymers of [2.2]paracyclophane and in situ silver(I) perfluoro-dicarboxylates: effects of the dicarboxylate spacers and conformations on the formation of complexes

Coordination polymers of [2.2]paracyclophane (pcp) with in situ silver(I) perfluoro-dicarboxylates characterized by single crystal X-ray analysis are described. Structures are found to strongly depend on the dicarboxylate spacer (n). With disilver(I) tetrafluorosuccinate ((CF₂)_n(COOAg)₂, n = 2), 3D network with composition of [Ag₄(pcp)(C₂F₄(CO₂)₂)₂] (1) forms in which silver salts afford infinite double chains and pcp act as linkages between chains. Changing the silver salt to disilver hexafluoroglutarate ((CF₂)_n(COOAg)₂, n = 3) produces 3D pillared-layer structure of composition of [Ag₄(pcp)(C₃F₆(CO₂)₂)₂] · THF (2) (THF = tetrahydrofuran), in which silver salts form 2D sheets and pcp act as pillars between the sheets. With silver octafluoroadipate (HO₂C(CF₂)_nCO₂Ag, n = 4), 2-fold interpenetrated diamond structure, [Ag₂(pcp)₂(HO₂CC₄F₈CO₂)₂]₂ · 2toluene (3), is obtained in which silver-anion chains and silver-pcp chains are connected with each other in the perpendicular manner. The three complexes represent unprecedented metal-organic networks of silver(I) multicarboxylates and polycyclic aromatic compounds. Additionally, the effects of the dicarboxylate conformations as well as the solvents on the resulting structures were discussed.     

Organometallic nickel(II) complexes with dithiophosphate, dithiophosphonate and monothiophosphonate ligands

The hydroxo complex [NBu₄]₂[Ni₂(C₆F₅)₄(μ-OH)₂] reacts with ammonium O,O^′-dialkyldithiophosphates, O-alkyl-p-methoxyphenyldithiophosphonate acids and ammonium O-alkylferrocenyldithiophosphonates in dichloromethane under mild conditions to give, respectively, [NBu₄][Ni(C₆F₅)₂{S(S)P(OR)₂}] (R=Me (1), Et (2), ⁱPr (3)) and [NBu₄][Ni(C₆F₅)₂{S(S)P(OR)Ar}] (Ar=p-MeOC₆H₄, R=Me (4), Et (5), ⁱPr (6); Ar=ferrocenyl; R=Me (7), Et (8), ⁱPr (9)). The monothiophosphonate nickel complexes [NBu₄][Ni(C₆F₅)₂{S(S)P(OR)(ferrocenyl)}] (R=Et (10), ⁱPr (11)) are obtained by reaction of the hydroxo complex with O-alkylferrocenyldithiophosphonate acids. Analytical (C, H, N, S), conductivity, and spectroscopic (IR, ¹H, ¹⁹F and ³¹P NMR, and FAB-MS) data were used for structural assignments. A single-crystal X-ray diffraction study of [NBu₄][Ni(C₆F₅)₂{S(S)P(OMe)(p-MeOC₆H₄)}] (4) and [NBu₄][Ni(C₆F₅)₂{S(O)P(OEt)(ferrocenyl)}] (10) shows that in both cases the coordination around the nickel atom es essentially square planar with NiC₂S₂ and NiC₂SO central cores, respectively.     

Syntheses and structures of Group 12 metal thioacetate anions, [M(SC{O}Me)nCl4−n] (n=3 and 4) and [Cd2Cl2(SC{O}Me)4]

We have utilized the possibility of altering the ratio of reactants to result in tetrahedral anions, [M(SC{O}Me)_nCl_4−n]²⁻ (n=3, 4) and [Cd₂Cl₂(SC{O}Me)₄]²⁻. Complexes of the formula [Ph₄P]₂[M(SC{O}Me)₄] (M=Zn(II) (1), Cd(II) (2) or Hg(II) (3)) were synthesized by the reaction of thioacetate ligand with the metal salts and Ph₄PCl in 4:1:2 molar ratio in suitable solvents. The geometry of Zn(II) in 1 is nearly tetrahedral and the distortion in tetrahedron increases in the order of 1<2<3 as observed from the SMS angles in the crystal structures. The tendency of monoanionic complexes [Ph₄P][M(SC{O}Me)₃] to react with 1 mole equivalent of Ph₄PCl resulted in complexes of the type [Ph₄P]₂[M(SC{O}Me)₃Cl] (M=Cd(II) (4) or Hg(II) (5)). In the structures of 4 and 5, three sulfur atoms and one chloride atom occupy the corners of the tetrahedron around the metal centers. However, in a 4:2:2 or 2:1:2 molar reaction of Me{O}CS⁻ with CdCl₂ and Ph₄PCl in aqueous medium resulted in a chloro bridged dimer, [Ph₄P]₂[Cd₂(μ-Cl)₂(SC{O}Me)₄] (6) as determined by X-ray crystallography.     

Photolytic CO-substitution reaction of organoiron thiocarboxylate derivatives CpFe(CO)2SCOR (R=alkyl, aryl) with diphosphines (Ph2P(CH2)nPPh2) (n=1-6): X-ray crystal structure of [CpFe(dppm)SCO(3,5-(NO2)2C6H3)]

The photolytic CO-substitution reaction of the organoiron thiocarboxylate complexes CpFe(CO)₂SCOR (R=CH₃, 2-CH₃C₆H₄, 2-NO₂C₆H₄, 4-NO₂C₆H₄, 3,5-(NO₂)₂C₆H₃) with diphosphines (Ph₂P(CH₂)_nPPh₂) [n=1 (dppm), n=2 (dppe), n=3 (dpppr), n=4 (dppb), n=5 (dppp), n=6 (dpph)] at room temperature using 1:2 (metal-ligand) molar ratio afforded exclusively the disubstituted complexes CpFe(Ph₂P(CH₂)_nPPh₂)SCOR when n=1, 2 and 3 and the monosubstituted analogs CpFe(CO)(Ph₂P(CH₂)_nPPh₂)SCOR when n=4, 5 and 6. This reaction was found to be strongly influenced by the backbone length of the diphosphine ligand, the nature of the R group of the thiocarboxylate moiety and the metal-ligand molar ratios. The crystal structure of CpFe(dppm)SCO(3,5-(NO₂)₂C₆H₃) was determined.     

Synthesis of dimethylcobalt(III) complexes containing trimethylphosphine and 2-formyl-phenolato- or 2-formyl-enolato(O:O) ligands

Substituted salicylaldehydes [C₆HR¹R²R³(CHO)(OH)] react with CoMe₃(PMe₃)₃ to afford 6-coordinate (cis-dimethyl)(2-formyl-phenolato)trans-bis(trimethylphosphine)cobalt(III) compounds Co[C₆HR¹R²R³(CHO)(O)Me₂](PMe₃)₂ (1: R¹ = H; R² = Me; R³ = tert-Bu; 2: R¹, R² = C₆H₄; R³ = H). Accordingly, substituted enolated malonic dialdehydes (CHO-CR⁴CR⁵-OH) react with CoMe₃(PMe₃)₃ to afford 6-coordinate (cis-dimethyl)(2-formyl-enolato)trans-bis(trimethylphosphine)cobalt(III) compounds Co[(CHO-CR⁴CR⁵-O)(Me)₂](PMe₃)₂ (3: R⁴, R⁵ = (CH₂)₂C₆H₄; 4: R⁴ = R⁵ = C₆H₅). In the molecular structure of 4, the cobalt atom is centred in an octahedral coordination geometry brought about by a six-membered chelate ring (O:O-ligand), cis-dimethyl and trans-trimethylphosphine groups. A reaction mechanism is suggested.     

Diphosphines as bridging ligands in polymeric and dimeric thione-S-ligated Ag(I) nitrate complexes

Reactions of silver(I) nitrate with equimolar amounts of the diphos ligands 1,4-bis(diphenylphosphino)butane (dppb) or 1,2-bis(diphenylphosphino)ethane (dppe) and some heterocyclic thiones (L) in acetonitrile/methanol solvent afforded mixed-ligand complexes, the nature of which was found to be strongly influenced by the backbone length of the diphosphine ligand. The longer chained diphos ligand formed a series of dinuclear complexes of the type [Ag(dppb)(L)]₂(NO₃)₂ with both the diphosphine and thione ligands acting as bridging ligands between the two four-coordinate pseudo-tetrahedrally coordinated metal centers. In the unique case of L=4-methyl-5-trifluoromethyl-4H-1,2,4-triazoline-3(2H)-thione (mftztH), the reaction proceeded under exclusion of the thione ligand from the coordination sphere and coordination of the nitrate anions instead, leading to the diphosphine-doubly bridged dimeric compound [Ag(dppb)(NO₃)]₂. On the other hand, the complexes produced when using the short bite 1,2-bis(diphenylphosphino)ethane (dppe) turned out to be diphosphine-bridged cationic polymers of the type [Ag(dppe)(L)₂]_n(NO₃)_n. The structures of one representative for each of the two aforementioned series of complex compounds, namely [Ag(dppb)(py2SH)]₂(NO₃)₂ · 2H₂O and [Ag(dppe)(pymtH)₂]_n(NO₃)_n, have been established by single-crystal X-ray diffraction.     

Synthesis and coordination of the bifunctionalized ylides Ph2P(CH2)n(Ph)2PCHCOOMe (n = 1, 2) and ketenylidene Ph2P(CH2)2(Ph)2PCCO to Pd and Pt complexes

In this paper it is reported the synthesis of the phosphonium salts [Ph₂P(CH₂)_n(Ph)₂PCH₂COOMe]Br (n = 1 (1), 2 (2)) and [Ph₂P(CH₂COOMe)(CH₂)_n(Ph)₂PCH₂COOMe]Br₂ (n = 3 (3)) derived from the reactions of the diphosphines dppm, dppe and dppp with methyl bromoacetate. By reaction of the monophosphonium salt of dppm and dppe with the strong base Na[N(SiMe₃)₂] the corresponding carbonyl stabilized ylides Ph₂P(CH₂)_n(Ph)₂PCHCOOMe (n = 1 (4), 2 (5)) were obtained. The Ph₂P(CH₂)₂(Ph)₂PCHCOOMe (5) ylide was reacted with Pd(II) and Pt(II) substrates. From these reactions were isolated exclusively complexes in which the ylide was chelated to the metal through the free phosphine group and the ylidic carbon atom. A further reaction of the Ph₂P(CH₂)₂(Ph)₂PCHCOOMe (5) ylide with 1.5 equiv. of Na[N(SiMe₃)₂] gives the bifunctionalized ketenylidene Ph₂P(CH₂)₂(Ph)₂PCCO (6) system. This cumulenic ylide reacts with Pt(II) complexes to form a chelated derivative in which IR and NMR spectra suggest the breaking of the CC bond of the -CCO group.     

Hydrothermal synthesis and structural investigation of silver magnesium complex of benzenehexacarboxylic acid (mellitic acid), Ag2Mg2[C6(COO)6] · 8H2O with two-dimensional layered structure

Crystal and molecular structure of silver magnesium mellitate, Ag₂Mg₂[C₆(COO)₆] · 8H₂O, was synthesized hydrothermally and characterized by X-ray structure analysis. The complex crystallizes in the monoclinic system, space group P2/n, with unit cell dimensions of a=7.4347(2), b=9.9858(2), c=14.4248(3) Å, β=99.2429(5)°, V=1055.01(4) ų, and Z=2. The structure was solved and refined to R=0.036 (R_w=0.045) for 1707 independent reflections [I_o>2σ(I_o)]. The Ag cations are coordinated by six carboxylic oxygen atoms of mellitate anions with composition of [C₆(COO)₆]⁶⁻ on the (1 0 1) plane; each mellitate anion linking three neighboring Ag distorted trigonal prisms produces a two-dimensional layered structure parallel to (1 0 1). The Mg cations, which are coordinated by four water molecules and two carboxylic oxygen atoms, are intercalated between the two-dimensional layer stacks. The carboxylate group coordinated to Mg and Ag cations serve as a tridentate ligand in that structure. The number of water molecules incorporated into the mellitate compound is controlled mainly by ionic radii of metal cation in the structure. Furthermore, the ionic radii of metal cations in the mellitate compound play an essential role in arrangement of mellitate anions in the structure, whether as a one-dimensional infinite chain, a two-dimensional layered structure, or a three-dimensional framework structure.     

Supramolecular coordination polymers of silver(I) with 2-isocyanopyridine or 1,2-phenylenediisocyanide

The silver(I) complexes [Ag{C₅H₄N(NC)}]_n(BF₄)_n (1), [Ag{C₅H₄N(NC)}₂]_n(BF₄)_n (2), [Ag{C₆H₄(NC)₂}]_n(BF₄)_n (3), and [Ag{C₆H₄(NC)₂}₂]_n(BF₄)_n (4) have been synthesized using different Ag:L ratios of 2-isocyanopyridine (or 2-pyridylisocyanide, CNPy-2) or 1,2-phenylenediisocyanide ligands. The polymeric complex 2 has been characterized by X-ray diffraction revealing a polymeric chain structure. Breaking the polymeric structure of [Ag{C₆H₄(NC)₂}]_n(BF₄)_n (3) with acetonitrile, the dimeric complex [Ag{(CN)₂C₆H₄)}(NCMe)₂]₂(BF₄)₂ (5) is formed, which has been also characterized by X-ray diffraction.     

Syntheses, thermal analyses, crystal structures and antimicrobial properties of silver(I)-saccharinate complexes with diverse diamine ligands

Five new silver(I)-saccharinate complexes [Ag₂(sac)₂(tmen)₂] (1), [Ag₂(sac)₂(deten)₂] (2), [Ag₂(sac)₂(dmen)₂] (3), [Ag(sac)(N,N-eten)] (4), and [Ag(sac)(dmpen)]_n (5); (sac = saccharinate, tmen = N,N,N′,N′-tetramethylethylenediamine, deten = N,N′-diethylethylenediamine, dmen = N,N′-dimethylethylenediamine, N,N-eten = N,N-diethylethylenediamine and dmpen = 1,3-diamino-2,2-dimethylpropan) have been synthesized and characterized by elemental analyses, IR, thermal analyses, single crystal X-ray diffraction and antimicrobial activities. The crystallographic analyses show that all the complexes crystallize in monoclinic space group P2₁/c. In 1, the sac ligand acts as a bridge to connect the silver centres through its imino N and carbonyl O atoms forming an eight-membered bimetallic ring in a chair conformation. Complex 2 has also a dimeric structure in which the monomeric [Ag(sac)(deten)] units are linked by Ag?Ag interactions. In 3, saccharinate ligand acts as a bridging bidentate ligand between two silver(I) centres through sulfonyl group and imino N atom, forming an alternating polymeric chain through the direction [0 1 0]. In 4, the inter-molecular N-H?O hydrogen bonds form one-dimensional polymeric chains through the a axis, and these linear chains are inter-connected to each other by N-H?O hydrogen bonds, which produce a chain of edge-fused and rings along [1 0 0]. Complex 5 is a coordination polymer in which the monomeric [Ag(dmpen)(sac)]_n units are linked by Ag?Ag interactions, and the dmpen ligand acts as a bridge between the silver(I) ions, forming a two-dimensional network parallel to the (1 0 0) plane.     

Tunable polymerization of silver complexes with organosulfur ligand: counterions effect, solvent- and temperature-dependence in the formation of silver(I)-thiolate(and/or thione) complexes

The reaction of pyridine-2-thiol with AgBF₄ and AgClO₄ in MeCN gave rise to polymeric compounds [{Ag(HPyS)₂}₂(BF₄)₂]_n (1) and [{Ag(HPyS)₂}₂(ClO₄)₂]_n (2) (HPyS=pyridine-2-thione), respectively, while the similar reaction of pyridine-2-thiol with AgNO₃ resulted in a polymeric compound [{Ag₄(HPyS)₆}(NO₃)₄]_n (3). X-ray single-crystal diffraction analyses showed that the cations of both 1 and 2 possess a single-metal-atom chain structure but that of 3 is a double-metal-atom chain structure. The difference between 1 (or 2) and 3 showed counterion effect in polymerization of silver-thione compounds. In the presence of water, the treatment of pyridine-2-thiol with AgBF₄ in DMF at 0 °C generated a polymeric compound [Ag(SPy)]_n (4) (Spy=pyridine-2-thiolate) with graphite-like layered array of silver ions. Compound 4 can convert into its isomer [Ag₆(SPy)₆]_n (5) through soaking in DMF for 1 month. However, the similar reaction of pyridine-2-thiol with AgBF₄ in MeCN-H₂O (v:v=40:1) at room temperature gave another layered polymeric compound [{Ag₅(Spy)₄(HPyS)}BF₄]_n (6). The preparation of 4, 5, and 6 showed that temperature and solvent exert influence on formation of silver-thiolate polymers. The reaction of AgNO₃ with K₂i-mnt (i-mnt=2,2-dicyanoethene-1,1,-dithiolate) and pyridine-2-thiol gave a polymer [Ag₄(μ₄-i-mnt)₂(μ-HPyS)₂(μ-HPyS)_4/2]_n (7) with one-dimensional (1-D) chain structure consisting of Ag₄ square planar cluster units linked by 1H-pyridine-2-thione ligand. The treatment of AgNO₃ with NaS₂CNEt₂ and pyridine-2-thiol in DMF resulted in another polymeric compound [Ag₄(μ₃-S₂CNEt₂)₂(μ₂-SPy)_4/2]_n (8). The preparation and characterization of these polymeric compounds demonstrated that polymerization of silver(I)-thione and silver(I)-thiolate complexes is tunable through controlling reaction conditions. Semiconducting property studies of 1-8 demonstrated that the electrical conductivity of 4 is 2.04×10⁻⁵ S cm⁻¹ at 25 °C and increases as temperature rises, and those of 1-3 and 5-8 are in the range of 1×10⁻¹²-1×10⁻¹⁵ S cm⁻¹ at room temperature and independent on the temperature, indicating that 1 is a semiconductor and the others are insulators.     

Synthesis and structural characterization of adducts of silver (I) diethyldithiocarbamate with P-donor ligands

Adducts of triorganophosphines PR₃, and diphosphines R₂P(CH₂)_nPR₂ with silver(I) diethyldithiocarbamate Ag(dtc) have been synthesized and characterized both in solution (¹H, ³¹P NMR) and in the solid state (IR, single-crystal X-ray structure analysis). The topology of the structures in the solid state was found to depend on the nature of the P-donor and on the Ag(dtc):P-donor stoichiometric ratio. In the mononuclear [(Ph₂MeP)₂Ag(dtc)] and [{(:CHPPh₂)₂}Ag(dtc)], four-coordinate P₂AgS₂ environments are found, as also in [(dtc)Ag(P′-dppm-P′)₂Ag(dtc)] where the two Ag(dtc) moieties are linked by the pair of bidentate, bridging, dppm ligands; by contrast the dppp adduct Ag(dtc):dppp (1:1) is an infinite one-dimensional polymer. In the other complexes [(R₃P)Ag(dtc)]₂ structurally defined, the silver environment is PAgS₃, two of the sulfur atoms drawn from the same dtc, now an unsymmetrical chelate, and one of the sulfur atoms bridged to the second silver atom.     

Arylboron complexes of the acids Ph2C(XH)CO2H (X = O, NH)

The acids Ph₂C(XH)CO₂H (X = O, NH) readily react with the triarylboron reagents BAr₃ (Ar = Ph, C₆F₅) to form the complexes [Ph₂C(O)CO₂BPh] (1) and [Ph₂C(NH₂)CO₂BPh₂] (2), Ph₂C(p-CH₃C₆H₄)CO₂H (3a) [in the presence of Et₃N the complex HNEt₃[Ph₂C(OH)CO₂B(C₆F₅)₃] (3b) was formed], and [Ph₂C(NH₃)CO₂B(C₆F₅)₃] (4), respectively. The synthesis and crystal structures of 1-4 (synchrotron radiation was necessary for 2) are reported.     

Silver(I) methanesulfonate complexes containing diphosphine ligands: Spectroscopic and structural characterization

1:1 and 2:1 adducts of diphosphine ligands R₂P(R′)_nPR₂ (dppm: R = Ph, R′ = CH₂, n = 1; dppe: R = Ph, R′ = CH₂, n = 2; dppp: R = Ph, R′ = CH₂, n = 3; dppb: R = Ph, R′ = CH₂, n = 4; dppf: R = Ph, R′ = ferrocenyl, n = 1) with silver(I) methanesulfonate have been synthesized and characterized both in solution (¹H, ³¹P NMR) and in the solid state (IR, single crystal X-ray structure analysis). The two different stoichiometries have been found to depend on the molar ratio of ligand to metal employed and the nature of the diphosphine ligand. In AgO₃SMe:dppp,dppb (1:1)₂, in the [Ag(P^P)₂Ag] arrays, the silver atoms are also bridged by anion oxygen atoms, in disparate fashion commensurate with the different Ag?Ag distances.     

The structure of a dinuclear silver(I) complex: Ag2[S2C2(CN)2] [P(C6H5)3]4

The crystal structure of the dimeric Ag maleonitriledithiolate complex, Ag₂[S₂C₂(CN)₂] [P(C₆- H₅)₃]₄ (1), has been performed. Complex 1 crystallizes in the space group P2₁/c with a = 12.2898(77), b = 23.8325(91), c = 23.1790(118) Å, β = 101.315(43)° and Z = 4. Refinement using 3253 reflections with F_o²>3σ(F_o²) yielded R = 0.0662, R_w= 0.0669. The most interesting aspect of the structure is the strong bridging interaction of the chelating maleonitriledithiolate ligand with the second Ag center, where a Ag-S distance of 2.478 Å is observed. The residual bonding capability of the sulfur atoms in the chelating anion [Ag(S₂C₂(CN)₂)(PPh₃)₂]⁻ for [Ag(PPh₃)₂]⁺ is demonstrated.     

Syntheses, spectroscopic and structural characterization of some (solvated) binuclear adducts of the form Ag(oxyanion):dpem(:S) (1:1(:x))2 (oxyanion = ClO4, F3CCO2, F3CSO3; dpem = Ph2E(CH2)EPh2 (E = P, As))

Syntheses, spectroscopic (IR, NMR and ESI MS) and single crystal X-ray structural characterizations are reported for a wide variety of adducts of Ag(oxyanion):dpem(:S) (1:1(:n))₂ (oxyanion = ClO₄, F₃CCO₂ (tfa) F₃CSO₃ (tfs); dpem = Ph₂E(CH₂)EPh₂) stoichiometry among which the basic Ag(Ph₂E(CH₂)EPh₂)₂Ag core is diversely perturbed by interactions with anions and solvent molecules. ESI MS and ³¹P NMR spectroscopy indicated that dinuclear species also exist in solution.     

Silver(I) complexes of fluorinated scorpionates: Ligand effects in silver catalyzed carbene insertion into C-H bonds in alkanes

Activation of C-H bonds of hydrocarbons via intermolecular carbene insertion has been investigated using tris(pyrazolyl)boratosilver(I) catalysts [MeB(3-(CF₃)Pz)₃]Ag(C₂H₄), [MeB(3-(C₂F₅)Pz)₃]Ag(C₂H₄) and [HB(3,5-(CF₃)₂Pz)₃]Ag(C₂H₄). Cyclopentane, 2-methylbutane, and 2,3-dimethylbutane were used as substrates. Carbenes derived from ethyl and tert-butyl diazoacetates have effectively been inserted into tertiary, secondary, as well as primary C-H bonds of hydrocarbons at room temperature using these catalysts. Tertiary C-H bonds in these substrates get preferentially activated over secondary C-H followed by primary C-H bonds. However, it is possible to increase the amount of primary C-H bond activated product by utilizing catalysts with increasingly acidic silver sites and sterically bulky tris(pyrazolyl)borate ligands. The carbene insertion into primary C-H bonds increases in the order: [MeB(3-(CF₃)Pz)₃]Ag(C₂H₄) < [MeB(3-(C₂F₅)Pz)₃]Ag(C₂H₄) < [HB(3,5-(CF₃)₂Pz)₃]Ag(C₂H₄). The carbene derived from tert-butyl diazoacetate with these catalysts shows slightly lower selectivity for primary C-H bonds compared to the ethyl diazoacetate-based carbene.