Polymeric complexes of silver(I) with diphosphine ligands: self-assembly of a puckered sheet network structure

The syntheses and structures of polymeric silver(I)-diphosphine complexes are reported, in which the silver(I) center is surrounded by 1, 2, or 3 phosphorus atoms. When rigid diphosphine ligands are used in combination with weakly coordinating anions, linear polymers are obtained that contain both diphosphine and anion bridges. However, with excess of a diphosphine with a long, flexible, spacer group, a remarkable puckered sheet structure, comprised of fused giant 54-membered rings, is obtained that is a coordination polymer analogue of laminated materials such as micas and clays. The polymeric chain and sheet structures may be considered to be formed by ring-opening polymerization of cyclic precursors.     

Binuclear alkynylplatinum(II) complexes

New face-to-face dimers of formula [Pt₂(CCR)₄(μ-dppm)₂], R = CF₃ or CH₃ and dppm = Ph₂PCH₂PPh₂, have been prepared but attempts to prepare binuclear diarylplatinum(II) complexes have been unsuccessful.     

Platinumolefin bond strength in Pt(PPh3)2(CH2CH2) and Pt(PPh3)2 {C(CN)2C(CN)2}

The enthalpy of the reaction: Pt(PPh₃)₂ (CH₂CH₂)(cryst.) + C(CN)₂C(CN)₂ (g) → Pt(PPh₃)₂ {C(CN)₂C(CN)₂}(cryst.) + CH₂ CH₂ (g) has been determined as ΔH₂₉₈=?155.8±8.0 kJ·mol^?1, from solution calorimetry. The interpretation, that the platinumethylene bond is much weaker than the platinumtetracyanoethylene bond, is contrary to conclusions drawn recently from electron emission spectroscopic studies, but in agreement with available structural data.     

Preparation and properties of some cationic binuclear platinum(I) complexes

Reaction of [Pt₂Cl₂(μ-dppm)₂] with ligands, L, in the presence of [PF₆^- gave stable cationic diplatinum(I) complexes [Pt₂L₂(μ-dppm)₂][PF₆]₂ where L = PMe₂Ph, PMePh₂, PPh₃, NH₃, C₅H₅N. Reaction of [Pt₂(NH₃)₂(μ-dppm)₂][PF₆]₂ with CO gave [Pt₂(CO)₂(μ-dppm)₂][PF₆]₂ and an unsymmetrical complex [Pt₂(CO)(C₅H₅N)(μ-dppm)₂][PF₆]₂ was also prepared. The compounds were characterized by vibrational and ¹H and ³¹P NMR spectroscopy and the presence of direct platinumplatinum bonds is indicated.     

Disilver(I) macrocycles: variation of cavity size with anion binding

Reaction of the N-methylated bis(amidopyridine) ligand, LL = C6H4(1,3-CONMe-4-C5H4N)2, with the silver salts AgNO3, AgO2CCF3, AgO3SCF3, AgBF4, and AgPF6 gave the corresponding cationic disilver(I) macrocycles [Ag2(micro-LL)2]X2, 2a-e. The transannular silver...silver distance in the macrocycles varies greatly from 2.99 to 7.03 A, and these differences arise through a combination of different modes ofanion binding and from the presence or absence of silver...silver secondary bonding. In all complexes, the ligand adopts a conformation in which the methyl group and oxygen atom of the MeNCO units are mutually cis, but the overall macrocycle can exist in either boat (X = PF6 only) or chair conformation. Short transannular silver...silver distances are found in complexes 2b,c, in which the anions CF3CO2- and CF3SO3- bind above and below the macrocycle, but longer silver...silver distances are found for 2a,d,e, in which the anions are present, at least in part, inside the disilver macrocycle. Easy anion exchange occurs in solution, and studies using ESI-MS indicate that the anion binding to form [Ag2X(micro-LL)2]+ follows the sequence X = CF3CO2- > NO3- > CF3SO3-.     

Molecular triangle of palladium(II) and its anion binding properties

The ligand 4(3H)-pyrimidone (Hpm) forms the complexes trans-[PdCl(2)(Hpm)(2)] and [Pd(PP)(Hpm)(2)](CF(3)SO(3))(2) (PP = Ph(2)PCH(2)PPh(2) or Ph(2)P(CH(2))(3)PPh(2)), with the neutral ligand (Hpm), and a bowl-like molecular triangle, [(Pd(bu(2)bipy)(mu-pm))(3)](3+) (bu(2)bipy = 4,4'-di-tert-butyl-2,2'-bipyridine), with the deprotonated ligand (pm). This triangular complex acts as a host for binding of several anionic guests.     

Ring-opening polymerisation of coordination compounds: a silver(I) network with both ring and polymer components

The terpyridyl ligand 2,6-C5H3N{C(=O)N(Me)-4-C5H4N}2, 1, combined with silver(I) salts to give the complexes [Ag2(1)2][BF4]2, 2, and [{Ag3(1)2}n][CF3SO3]3n, 3; the network structure of complex contains both macrocyclic units [Ag2(mu-1)2]2+ and ring-opened polymeric units [{Ag(mu-1)}n]n+.     

Reactions and properties of some trimethyleneplatinum(IV) complexes: VII. Kinetics and mechanism of displacement of cyclopropane by alkenes

The kinetics of the reaction of alkenes (e.g. cis-pent-2-ene, hex-1-ene, cyclopentene) with [$\text{PtX}{}_2\text{(CH}{}_2\text{CH}{}_2\text{C}$H₂)(THF)₂] (X = Cl or Br, THF = tetrahydrofuran) or with [$\text{PtCl}{}_2\text{(CHPhCH}{}_2\text{C}$H₂)(THF)₂] in THF solution have been studied. The reactions occur with displacement of cyclopropane or phenylcyclopropane to give [PtCl₂(olefin)(THF)], and follow essentially second order kinetics, first order in both platinum complex and olefin. The mechanism of reaction is discussed.     

Tetraphosphinitoresorcinarene complexes: cationic silver(I) and copper(I) halide complexes as mercurate(II) anion receptors

The reactions of mercury(II) halides with the tetraphosphinitoresorcinarene complexes [P4M5X5], where M=Cu or Ag, X=Cl, Br, or I, and P4=(PhCH2CH2CHC6H2)4(O2CR)4(OPPh2)4 with R=C6H11, 4-C6H4Me, C4H3S, OCH2CCH, or OCH2Ph, have been studied. The reactions of the complexes with HgX2 when M=Ag and X=Cl or Br occur with elimination of silver(I) halide and formation of [P4Ag2X(HgX3)], but when M=Ag and X=I, the complexes [P4Ag4I5(HgI)] are formed. When M=Cu and X=I, the products were the remarkable capsule complexes [(P4Cu2I)2(Hg2X6)]. When M=Ag and X=I, the reaction with both CuI and HgI2 gave the complexes [P4Cu2I(Hg2I5)]. Many of these complexes are structurally characterized as containing mercurate anions weakly bonded to cationic tetraphosphinitoresorcinarene complexes of copper(I) or silver(I) in an unusual form of host-guest interaction. In contrast, the complex [P4Ag4I5(HgI)] is considered to be derived from an anionic silver cluster with an iodomercury(II) cation. Fluxionality of the complexes in solution is interpreted in terms of easy, reversible making and breaking of secondary bonds between the copper(I) or silver(I) cations and the mercurate anions.