18517-48-1Relevant articles and documents
Regioselective competition between the formation of seven-membered and five-membered cyclometalated platinacycles preceded by Csp2-Csp3 reductive elimination
Anderson, Craig M.,Greenberg, Matthew W.,Spano, Lucia,Servatius, Labeeby,Tanski, Joseph M.
, p. 27 - 36 (2016)
A mixture of seven-membered and five-membered platinacycle complexes are eventually formed after a series of substitution, oxidative addition, and reductive elimination reactions between the platinum dimer, cis-[Pt2Me4(μ-SMe2)2] and the naphthyl-derived ?N chelate ligands, (8-XC10H6CH = N-R), X = I, Br; R = phenyl and 4-Cl-benzyl. From the tethered ligand, either an sp2 C-H bond can be activated forming a five-membered ring or an sp3 C-H bond can be activated forming a seven-membered ring. All compounds have the imine included in the platinacycle. The ratio of complexes as a function of ring size varies depending on ligand architecture of the chelate ligand and the nature of other ligands in the coordination sphere. The cyclometalated platinum complexes have been characterized by NMR spectroscopy. One complex with a seven-membered ring was characterized crystallographically. Reductive elimination reactions of isolated and/or identified cyclometalated, six-membered platinum(IV) compounds [PtMe2Br{C10H6CH = NCH2(4-ClC6H4)}L] and [PtMe2Br{C10H6CH = N(C6H5)}L] (L = SMe2) to form Csp3-Csp2 bonds, followed by competition between Csp2-H and Csp3-H bond activation are also reported.
A Sound Sequence to Triphenylphosphino Dibromoplatinum(II) Complexes – Solvothermal Preparation of trans-[PtBr(μ-Br)(PPh3)]2
Fioco, David,Belli Dell'Amico, Daniela,Labella, Luca,Marchetti, Fabio,Samaritani, Simona
, p. 3970 - 3974 (2019/09/09)
A sound synthetic procedure for the preparation of trans-[PtBr(μ-Br)(PPh3)]2 is described. The species was fully characterized and used to obtain [PtBr2(PPh3)(L)] complexes (L = DMSO, p-toluidine, pyridine) by a bridge-splitting reaction. All products were fully characterized by NMR spectroscopy, together with cis-[PtBr2(PPh3)(NCCH3)], obtained as an intermediate in the synthesis of the dinuclear precursor. Cis-[PtBr2(PPh3)(NCCH3)] was also studied by X-ray diffraction.
Pt-catalysed intermolecular hydroamination of non-activated olefins using a novel family of catalysts: Arbuzov-type phosphorus metal complexes
Rodriguez-Zubiri, Mireia,Anguille, Stéphane,Brunet, Jean-Jacques,Daran, Jean-Claude
, p. 103 - 111 (2013/09/24)
The catalytic system "PtBr2(0.3 mol%)/2P(OR) 3/10nBu4PBr" (R = alkyl) discovered recently in our group, allows good to excellent catalytic activities for the intermolecular hydroamination of ethylene and higher α-olefins (1-hexene) with aniline type amines to give the expected N-ethyl- (1) and N,N-diethyl-anilines (2) along with 2-methyl-quinoline (3). A poisoning effect of alkyl and aromatic phosphines has been observed. This effect could be minimised using small amounts of molecular iodide which reacts with phosphorus ligands to form non-coordinating well-described ionic species. Interestingly, beneficial effects of added P(OR)3 (R = alkyl) have been pointed out and further investigated. In this way, a new potential family of Arbuzov-type phosphorus-metal complexes has been suggested to be responsible for good catalytic activities found when using P(OR)3 alkyl phosphites rather than PR3 (R = alkyl, aromatic) and P(OPh)3 co-catalysts.
σ-bond metathesis between M-X and RC(O)X′ (M = Pt, Pd; X, X′ = Cl, Br, I): Facile determination of the relative Δ G values of the oxidative additions of RC(O)X to an M(0) complex, evidence by density functional theory calculations, and synthetic applications
Kuniyasu, Hitoshi,Sanagawa, Atsushi,Nakane, Daisuke,Iwasaki, Takanori,Kambe, Nobuaki,Bobuatong, Karan,Lu, Yunpeng,Ehara, Masahiro
supporting information, p. 2026 - 2032 (2013/05/09)
The novel utility of the ligand exchange reaction between M-X and RC(O)X′ (X, X′ = halogen; R = aryl, alkyl) is described. The relative ΔGs (ΔΔGs) of the oxidative additions of acid halides RC(O)X to M(PPh3)2Ln (M = Pt, Pd) were determined using the halogen-exchange reactions between X of trans-M(X)[C(O)R](PPh3)2 and X′ of RC(O)X′. Experimental thermodynamics data are reasonably consistent with those obtained by density functional theory (DFT) calculations. Activation parameters obtained by experiments as well as a systematic DFT study supported the fact that reactions occurred through slightly distorted quadrangular pentacoordinated σ-bond metatheses, in which the Cl atom underwent a more indirect course than the Br atom. Moreover, exchange reactions were employed as the accessible prototype for the conversion of halogen ligands of nickel triad complexes into heavier halogen ligands.
Diverse C-C bond-forming reactions of bis(carbene)platinum(II) complexes
Klet, Rachel C.,Labinger, Jay A.,Bercaw, John E.
, p. 6652 - 6657 (2012/11/07)
The platinum(0) complex Pt(PPh3)4 catalyzes coupling of the carbene ligands of (CO)5Cr{C(OMe)(p-MeOC6H 4)} (1). The stable bis(carbene)platinum(II) complexes Cl 2Pt{C(OMe)(Me)}2
Tin(II) halide insertion or halogen exchange in the reactions of dihaloplatinum(II) complexes with tin(II) halide
Momeni, Badri Z.,Kazmi, Hoori,Najafi, Atefeh
, p. 1618 - 1627 (2011/10/31)
Reactions of SnCl2 with the complexes cis-[PtCl 2(P2)] (P2=dppf (1,1′- bis(diphenylphosphino)ferrocene), dppp (1,3-bis(diphenylphosphino)propane=1, 1′-(propane-1,3-diyl)bis[1,1-diphenylphosphine]), dppb (1,4-bis(diphenylphosphino)butane=1,1′-(butane-1,4-diyl)bis[1, 1-diphenylphosphine]), and dpppe (1,5-bis(diphenylphosphino)pentane=1,1′- (pentane-1,5-diyl)bis[1,1-diphenylphosphine])) resulted in the insertion of SnCl2 into the Pt-Cl bond to afford the cis-[PtCl(SnCl 3)(P2)] complexes. However, the reaction of the complexes cis-[PtCl2(P2)] (P2=dppf, dppm (bis(diphenylphosphino)methane=1,1′-methylenebis[1,1-diphenylphosphine]), dppe (1,2-bis(diphenylphosphino)ethane=1,1′-(ethane-1,2-diyl)bis[1,1- diphenylphosphine]), dppp, dppb, and dpppe; P=Ph3P and (MeO) 3P) with SnX2 (X=Br or I) resulted in the halogen exchange to yield the complexes [PtX2(P2)]. In contrast, treatment of cis-[PtBr2(dppm)] with SnBr2 resulted in the insertion of SnBr2 into the Pt-Br bond to form cis-[Pt(SnBr3) 2(dppm)], and this product was in equilibrium with the starting complex cis-[PtBr2(dppm)]. Moreover, the reaction of cis-[PtCl 2(dppb)] with a mixture SnCl2/SnI2 in a 2 : 1 mol ratio resulted in the formation of cis-[PtI2(dppb)] as a consequence of the selective halogen-exchange reaction. 31P-NMR Data for all complexes are reported, and a correlation between the chemical shifts and the coupling constants was established for mono- and bis(trichlorostannyl) platinum complexes. The effect of the alkane chain length of the ligand and SnII halide is described. Copyright
Cooperation between cis and trans influences in cis-Pt II(PPh3)2 complexes: Structural, spectroscopic, and computational studies
Rigamonti, Luca,Forni, Alessandra,Manassero, Mario,Manassero, Carlo,Pasini, Alessandro
, p. 123 - 135 (2010/03/04)
The relevance of cis and trans influences of some anionic ligands X and Y in cis-[PtX2(PPh3)2] and cis-[PtXY(PPh 3)2] complexes have been studied by the X-ray crystal structures of several derivatives (X2 = (AcO)2 (3), (NO3)2 (5), Br2 (7), I2 (11); and XY = Cl(AcO) (2), Cl(NO3) (4), and Cl(NO2) (13)), density functional theory (DFT) calculations, and one bond Pt-P coupling constants, JPtp. The latter have allowed an evaluation of the relative magnitude of both influences. It is concluded that such influences act in a cooperative way and that the cis influence is not irrelevant when rationalizing the 1 JPtp values, as well as the experimental Pt-P bond distances. On the contrary, in the optimized geometries, evaluated through B3LYP/def2-SVP calculations, the cis influence was not observed, except for compounds CIPh (21), Ph2 (22), and, to a lesser extent, Cl(NO2) (13) and (NO2) 2(14). A natural bond order analysis on the optimized structures, however, has shown how the cis influence can be related to the s-character of the Pt hybrid orbital involved in the Pt-P bonds and the net atomic charge on Pt. We have also found that in the X-ray structures of cis-[PtX 2(PPh3)2] complexes the two Pt-X and the two Pt-P bond lengths are different each other and are related to the conformation of the phosphine groups, rather than to the crystal packing, since this feature is observed also in the optimized geometries.
Quantification of cis and trans influences in [PtX(PPh3) 3]+ complexes. A 31P NMR study
Rigamonti, Luca,Rusconi, Michele,Manassero, Carlo,Manassero, Mario,Pasini, Alessandro
, p. 3498 - 3505 (2011/02/16)
In [PtX(PPh3)3]+ complexes (X = F, Cl, Br, I, AcO, NO3, NO2, H, Me) the mutual cis and trans influences of the PPh3 groups can be considered constants in the first place, therefore the one bond Pt-P coupling constants of P (cis) and P(trans ) reflect the cis and trans influences of X. The compounds [PtBr(PPh3)3](BF4) (2), [PtI(PPh 3)3](BF4) (3), [Pt(AcO)(PPh3) 3](BF4) (4), [Pt(NO3)(PPh3) 3](BF4) (5), and the two isomers [Pt(NO 2-O)(PPh3)3](BF4) (6a) and [Pt(NO2-N)(PPh3)3](BF4) (6b) have been newly synthesised and the crystal structures of 2 and 4·CH 2Cl2·0.25C3H6O have been determined. From the 1JPtP values of all compounds we have deduced the series: I > Br > Cl > NO3 > ONO > F > AcO > NO2 > H > Me (cis influence) and Me > H > NO2 > AcO > I > ONO > Br > Cl > F > NO 3 (trans influence). These sequences are like those obtained for the (neutral) cis- and trans-[PtClX(PPh3)2] derivatives, showing that there is no dependence on the charge of the complexes. On the contrary, the weights of both influences, relative to those of X = Cl, were found to depend on the charge and nature of the complex.
Thallium(III) complexes of the metalloligands [Pt2(μ-S)2(PPh3)4] and [Pt2(μ-Se)2(PPh3)4]
Rose, Sarah L.,Henderson, William,Nicholson, Brian K.,Hor, T.S. Andy
, p. 5237 - 5244 (2010/05/01)
Reactions of [Pt2(μ-S)2(PPh3)4] with the diarylthallium(III) bromides Ar2TlBr [Ar = Ph and p-ClC6H4] in methanol gave good yields of the thallium(III) adducts [Pt2(μ-S)2(PPh3)4TlAr2]+, isolated as their BPh4- salts. The corresponding selenide complex [Pt2(μ-Se)2(PPh3)4TlPh2]BPh4 was similarly synthesised from [Pt2(μ-Se)2(PPh3)4], Ph2TlBr and NaBPh4. The reaction of [Pt2(μ-S)2(PPh3)4] with PhTlBr2 gave [Pt2(μ-S)2(PPh3)4TlBrPh]+, while reaction with TlBr3 gave the dibromothallium(III) adduct [Pt2(μ-S)2(PPh3)4TlBr2]+[TlBr4]-. The latter complex is a rare example of a thallium(III) dihalide complex stabilised solely by sulfur donor ligands. X-ray crystal structure determinations on the complexes [Pt2(μ-S)2(PPh3)4TlPh2]BPh4, [Pt2(μ-S)2(PPh3)4TlBrPh]BPh4 and [Pt2(μ-S)2(PPh3)4TlBr2][TlBr4] reveal a greater interaction between the thallium(III) centre and the two sulfide ligands on stepwise replacement of Ph by Br, as indicated by shorter Tl-S and Pt?Tl distances, and an increasing S-Tl-S bond angle. Investigations of the ESI MS fragmentation behaviour of the thallium(III) complexes are reported.
Coordination chemistry of P-rich phosphanes and silylphosphanes. XIII [1]. ~[η2-{tBu2P-P=PtBu 2}PtBr(PPh3)]
Kovacs,Krautscheid,Matern,Fritz,Pikies
, p. 1088 - 1092 (2008/10/09)
[η2-{tBu2P-P=PtBu 2}PtBr(PPh3)] 1 is the first transition metal complex compound resulting from a phosphinophosphinidene-phosphorane. The yellow crystals of 1 (fp. 201-203°C, decomp.) were obtained by reacting tBu2P-P=P(Br)tBu2 with either (Ph3P)2Pt · C2H4, or with Pt(PPh3)4, resp. Compound 1 crystallizes triclinic in the space group P1 (no. 2) with a = 1076.80(8) pm, b = 1344.61(8) pm, c = 1381.16(9) pm, α= 81.773(6)°, β = 85,110(8), γ = 88,776(7).
