40,567 research outputs found
Convenient synthesis of cationic allylplatinum(II) complexes with tertiary phosphines by oxidative allyl transfer from ammonium cations to platinum(0) substrates. Crystal and molecular structures of eta(3)-propenyl- and eta(3)-2-methylpropenyl-bis-(triphenylphosphine)platinum(II)perchlorate
No full textA large variety of cationic eta(3)-allylplatinum(II) complexes of the type [Pt(eta(3)-CH2C(R)C(R')(R ")(PPh3)(2)](+)(1a-f) are prepared in high yield by oxidative allyl transfer from the ammonium cations [NEt3CH2C(R) C(R')(R ")](+) to [Pt(eta(2)-C2H4)(PPh3)(2)]. A similar reaction of [NEt3CH2C(R)-C(R')(2)](+) with [Pt(cod)(2)] yields the related complexes [Pt(eta(3)-CH2C(R)C(R')(2)(cod)](+) (2a-c), indicating a rather general feasibility of such synthetic route. The 1,5-cyclooctadiene ligand of complexes 2a,e can be easily displaced by mono- and bidentate tertiary phosphines. The solution behaviour of the cationic eta(3)-allyl platinum(II) complexes has been studied by multinuclear NMR spectroscopy. The solid state structures of the complexes [Pt(eta(3)-CH2CHCH2)(PPh3)(2)](+) (1a) and [Pt(eta(3)-CH2C(Me)CH2)(PPh3)(2)](+) (1b) have been determined by X-ray analyses. In Ib, the 2-methylpropenyl ligand is symmetrically eta(3)-bound to platinum and assumes a unique orientation relative to the average coordination plane. In la, however, the propenyl ligand is disordered in two opposite orientations with occupation factors of 0.65 and 0.35. In the orientation with 0.65 occupation factor, the allyl ligand is symmetrically eta(3)-bound to the metal, whereas, in the opposite orientation the C-C bond distances within the allyl group are considerably different [1.46(4) and 1.23(4) Angstrom] with the three allyl carbon atoms being at roughly equal distances from platinum. Even though the C3H5 group is affected by large anisotropic thermal motion, the observed asymmetry may also arise from a prevailing eta(1), eta(2) coordination of the ligand in the solid
Synthesis, characterization and cytotoxic activity of substituted benzyl iminoether Pt(II) complexes of the type cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-R}(2)] (R = Me, OMe, F). X-ray structure of trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-F}(2)]
No full textNew substituted benzyl iminoether derivatives of the type cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-R}(2)] (R = Me (1a, 2a), OMe (3a, 4a), F (5a, 6a)) have been synthesized and characterized by elemental analyses, FT-IR spectroscopy and NMR techniques. The iminoether ligands are in the E configuration, which is stable in solution and in the solid state, as confirmed by the H-1 NMR data. Complex trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-F}(2)] (6a) was also characterized by an X-ray diffraction study. Complexes 1 a-6a have been tested against a panel of human tumor cell lines in order to evaluate their cytotoxic activity. cis-Isomers were significant more potent than the corresponding trans-isomers against all tumor cell lines tested; moreover, complexes la and 5a showed IC50 values from about 2-fold to 6-fold lower than those exhibited by cisplatin, used as reference platinum anticancer drug
Tapinauchenius gretae Cifuentes & Bertani, 2022, n. sp.
No full textTapinauchenius gretae n. sp. (Figs 19, 21, 23, 122–144) Diagnosis. Females of Tapinauchenius gretae n. sp. resemble those of T. brunneus by the large lobe on the spermathecae apex (Fig. 129). They differ by spermathecae shape, having the same width almost all of its length. Males of Tapinauchenius gretae n. sp. resemble those of T. brunneus by the embolus in dorsal view roughly straight with a pronounced curvature to retrolateral side at its distal portion (Fig. 125). They differ by the longer embolus, more than 3.5 times subtegulum length (Fig. 122) and by the slender embolus in dorsal view (Fig. 125). Etymology. The specific epithet is a matronym in honor of Greta Thunberg, a young Swedish environmental activist who has fought against climate change and for the preservation of the planet. Type material. Holotype male from Brazil, Amazonas, Iranduba, Vila de Paricatuba [3°05’00”S, 60°14’32”W] R. Bertani & M. Q. Almeida col., 04 November 2017 (MZUSP 76536), 2 paratype females, M. Q. Almeida col., 22 April 2017 ( INPA 9100). Other material examined. BRAZIL: Amazonas: Presidente Figueiredo [2°03’09”S, 60°01’27”W], in Acariquara (Minquartia guianensis) tree trunk, 1 male, M. Q. Almeida, 15 January 2008 (INPA 9097); Manaus [3°04’S, 59°59’W] 1 male, in Acariquara (Minquartia guianensis) tree, 12 July 2017, M. Q. Almeida (INPA 4882); Iranduba, Vila de Paricatuba (3°05’00”S, 60°14’32”W), 1 female, R. Bertani and M. Q. Almeida col., 04 November 2017 (MZUSP 76534); 1 female, same data and collectors (MZUSP 76535); 1 male, same data and collectors (MZUSP 76537); 1 female, same data and collectors (MZUSP 76538); 1 female, R. Bertani, M. Q. Almeida and F. F. Xavier, 02 July 2018 (MNRJ 7703); Nhamundá [2°11’26”S, 56°42’54”W], boca do Figueiredo, in bromeliad, 1 male, E.P.A. col. 18 January1968 (MZUSP 10852); Novo Airão (2°37’41.5”S, 60°57’13.6”W), 1 male, R. Bertani and M.E.E.S Oliveira, 06 November 2017 (MNRJ 7704); 1 male, same data and collectors (MNRJ 7705); Rio Preto da Eva [2°41’54”S, 59°42’02W], 1 male, M. Q. Almeida col., 06 May 2015 (INPA 9099). Description. Male holotype (MZUSP 76536). Total length, not including chelicerae or spinnerets 20.55. Carapace 9.75 long, 8.37 wide, 2.01 high. Chelicera: 4.81 long. Legs (femur, patella, tibia, metatarsus, tarsus, total): I: 10.75, 5.54, 9.54, 8.22, 4.10, 38.15; II: 9.60, 4.98, 8.06, 7.72, 3.99, 34.35; III: 7.86, 3.94, 6.30, 7.21, 3.61, 28.92; IV: 10.10, 4.44, 9.29, 9.82, 3.53, 37.18; Palp: 6.37, 3.64, 5.39, -, 1.51, 16.91. Midwidths: femora I–IV= 1.86, 1.82, 1.88, 1.75, palp= 1.22; patellae I–IV= 1.51, 1.71, 1.69, 1.78, palp= 1.65; tibiae I–IV= 1.40, 1.26, 1.66, 1.43, palp= 1.22; metatarsi I–IV= 0.98, 0.87, 0.94, 0.82; tarsi I–IV= 0.88, 0.79, 0.92, 0.78, palp= 1.32. Abdomen: 10.80 long, 6.45 wide. Spinnerets: PMS, 1.43 long, 055 wide, 0.26 apart; PLS, 2.34 basal, 1.71 middle, 2.80 distal; midwidths 0.99, 0.73, 0.63, respectively. Carapace: 1.16 times longer than wide; cephalic region slightly raised, thoracic striae conspicuous. Fovea: shallow, straight, 0.96 wide. Eyes: tubercle 0.40 high, 1.36 long, 2.46 wide. Clypeus: absent. Anterior row straight, posterior recurved. Eye size and interdistances: AME 0.64, ALE 0.51, PME 0.32, PLE 0.41, AME–AME 0.35, AME–ALE 0.17, AME–PME 0.17, ALE–ALE 1.75, ALE–PME 0.33, PME–PME 1.37, PME– PLE 0.13, PLE–PLE 1.91, ALE–PLE 0.23. Maxilla: length to width 1.66. Cuspules: ca. 135 spread over ventral inner heel. Labium: 1.21 long, 1.58 wide, with ca. 114 cuspules spaced by one diameter from each other on anterior third. Chelicera: basal segment with 8 teeth in row. Sternum: 4.92 long, 3.89 wide. Legs: Formula: I = IV II III. Length leg IV to leg I: 0.97. Scopula: Tarsi I–IV fully scopulate; IV with a few sparse setae. Metatarsi I–II fully scopulate; III 2/3 distal; IV 1/3 distal. IV divided by rows of setae. Spination: Palps and legs (ventral apical: tibia/metatarsi): Palp 0; I: 1 behind retrolateral process of tibial apophysis; II: 2/0; III 1/2; IV 1/1. Tibial apophysis (Figs 126–128) with two processes, retrolateral larger than prolateral, one spine at side of prolateral, another on apical part of retrolateral process. A conspicuous rounded protuberance behind retrolateral process. Metatarsus I folds on retrolateral side of tibial apophysis. Palp (Figs 122–125): tegulum length 0.77, width 1.01, embolus proximal width 0.43, length 2.86. Embolus proximal portion straight. Embolus length to tegulum: 3.71, roughly straight in dorsal view with pronounced curvature to retrolateral side at its distal portion. Embolus distal portion narrows abruptly ending in curved tip. Color pattern (preserved in alcohol): Carapace, chelicerae, legs, palps and abdomen brown covered with light brown setae. Maxillae, sternum, labium and anterior half of coxa brown, posterior half of coxae light brown. Description. Female paratype (INPA 9100). Total length, not including chelicerae or spinnerets 30.02. Carapace 14.92 long, 10.76 wide, 8.04 high. Chelicera: 9.96 long. Legs (femur, patella, tibia, metatarsus, tarsus, total): I: 11.35, 7.51, 10.41, 8.97, 5.09, 43.33, II: 10.98, 7.58, 10.69, 8.98, 4.58, 42.81; III: 8.70, 5.64, 7.41, 8.44, 4.12, 34.31; IV: 11.01, 6.10, 10.81, 11.58, 3.86, 43.36; Palp: 7.44, 4.90, 5.50, -, 5.81, 23.6. Midwidths: femora I–IV= 2.19, 2.09, 2.36, 2.42, palp= 2.13; patellae I–IV= 2.11, 2.45, 2.07, 2.51, palp=2.37; tibiae I–IV= 2.03, 1.88, 2.27, 2.17, palp= 1.85; metatarsi I–IV=1.75, 1.69, 1.39, 1.33; tarsi I–IV= 1.65, 1.47, 1.55, 1.24, palp= 1.50. Abdomen: 14.96 long, 9.44 wide. Spinnerets: PMS, 1.05 long, 0.48 wide, 0.29 apart; PLS, 1.37 basal, 1.22 middle, 1.82 distal; midwidths 0.71, 0.73, 0.61, respectively. Carapace: 1.39 times longer than wide; cephalic region slightly raised, thoracic striae conspicuous. Fovea: deep, straight, 0.84 wide. Eyes: eye tubercle 0.57 high, 0.88 long, 1.55 wide. Clypeus: absent. Anterior eye row straight, posterior slightly recurved. Eye size and interdistances: AME 0.35, ALE 0.33, PME 0.19, PLE 0.30, AME–AME 0.19, AME–ALE 0.13, AME–PME 0.13, ALE–ALE 1.10, ALE–PME 0.20, PME–PME 0.89, PME–PLE 0.11, PLE–PLE 1.18, ALE–PLE 0.18. Maxilla: length to width 1.60. Cuspules: ca. 148 spread over ventral inner heel. Labium: 1.05 long, 1.19 wide, with ca. 136 cuspules spaced by one diameter from each other on anterior third. Chelicera: basal segment with 9 teeth in row. Sternum: 3.53 long, 2.54 wide. Legs: Formula: I = IV II III. Length leg IV to leg I: 1.00. Scopula: Tarsi I–IV fully scopulate; IV with a few sparse setae. Metatarsi I–II fully scopulate; III 1/2 distal; IV 1/4 distal. IV divided by rows of setae. Spination: Palps and legs (ventral apical: tibia/metatarsi): Palp 0; I: 0/0; II 2/0; III 0/ 2; IV 0/2. Spermathecae (Fig. 129): Two spermathecae completely separated, elongate and almost the same width all its length, with a sclerotized apical rounded lobe of almost half diameter of spermatheca midwidth. Color pattern (in vivo): Carapace, legs, palpal femora and tibiae brown, with blue-violet shades; abdomen purple with a proximal transverse dark line connected with a central vertical line forming a “T” (Fig. 138). Distribution. Brazil (Figs 21, 23).Published as part of Cifuentes, Yeimy & Bertani, Rogerio, 2022, Taxonomic revision and cladistic analysis of the tarantula genera Tapinauchenius Ausserer, 1871, Psalmopoeus Pocock, 1985, and Amazonius n. gen. (Theraphosidae, Psalmopoeinae), pp. 1-123 in Zootaxa 5101 (1) on pages 57-62, DOI: 10.11646/zootaxa.5101.1.1, http://zenodo.org/record/625322
Evidence for platinum(II)-vinylidene complexes and their reactions with water to give hydrocarbons and olefins
No full textTreatment of the alkynyl complexes trans-[Pt(Me)(CCR)(PPh3)2] (R=p-tolyl (1a), Ph (1b)) at low temperature in a CD2Cl2 solution with stoichiometric amounts of the acids HBF4·Et2O or CF3SO3H affords the corresponding vinylidene derivatives trans-[Pt(Me){=C=C(H)R}(PPh3)2]X (R=p-tolyl, X=BF4 (2aBF4); R=p-tolyl, X=CF3SO3 (2aCF3SO3); R=Ph, X=BF4 (2bBF4)) on the basis of 1H- and 31P{1H}-NMR data. The reactions of the in situ generated complexes 2 with water, which were followed by 1H- and 31P{1H}-NMR, lead to the formation of a mixture of the carbonyl complex [Pt(Me)(CO)(PPh3)2]X (3) and the hydroxo-bridged dinuclear compound [Pt(μ-OH)(PPh3)2]2X2 (4) in a ca. 1:2 ratio. The formation of 3 and 4 is accompanied with the liberation of hydrocarbons R-CH3 and olefins CH3CH=CHR (R=p-tolyl, Ph), respectively, which arise from the vinylidene ligand likely via an hydroxycarbene intermediate
NUCLEOPHILIC-ATTACK BY 2-PYRIDYLPALLADIUM(II) AND PLATINUM(II) COMPLEXES ON THE ORGANIC CHLORIDES CLCH2R (R = COME, CN, PH, CL)
No full textThe 2-pyridyl complexes trans-[MCl(C5H4N-C2)(PPh3)2] (M = Pd, 1a; M = Pt, 1b), [MCl(C5H4N-C2)(dppe)] (M = Pd, 2a; M = Pt, 2b) and [M(dmtc)(C5H4N-C2)(PPh3)] (M = Pd, 3a; M = Pt, 3b) react with the chlorides ClCH2R (R = COMe, CN, Ph) to give cationic products containing the 2-pyridylium ligands (1-CH2R)C5H4N-C2. The rate of nucleophilic displacement of the chloride ion from ClCH2R depends on the central metal (Pt > Pd), on the coordination geometry (1 CN > Ph for the reactions with 3b). Like 1b and 2b, complex 3b also reacts with dichloromethane to give [Pt(dmtc){(1-CH2Cl)C5H4N-C2}(PPh3)]+. The reaction of the binuclear compound [{PdCl(mu-C5H4N-C2,N)(PPh3)}2] with chloroacetone in the presence of chloride ion yields the zwitterionic derivative cis-[PdCl2{(1-CH2COMe)C5H4N-C2}(PPh3)]. The cationic products have been isolated and characterized as perchlorate salts
Regioselective ring opening of [(perfluoroalkyl)methyl] oxiranes with N-nucleophiles
No full textThe reactions of C8F17CH2CHCH2O with some primary and secondary aliphatic amines affording selective ring opening at C-beta are reported. The reactions with secondary amines (HNRR2)-R-1 (R-1 = R-2 = Et; R-1 = Bu-t, R-2 = CH2CH2O(CO)C(CH3)=CH2; R-1 = Et, R-2 = CH2CH2OH; R-1 =R-2 =CH2CH2OH) gave the corresponding C8F17CH2-CH(OH)-CH2-(NRR2)-R-1 derivatives. For R-1 = Et, R-2 = CH2CH2OH; R-1 =R-2 = CH2CH2OH, the reactions proceed through the selective nucleophilic attack of the NH moiety with no evidence of reactivity of the OH group. The reactions with the primary amines, allylamine and n-hexamethylenediamine, gave different products depending on reaction conditions. (c) 2005 Elsevier B.V. All rights reserved
Alessandro Bosi, Generazioni e ideologia, in Leonardo Angelini, Deliana Bertani (a cura di), L’adolescenza nell’epoca della globalizzazione, Unicopli, Milano, 2005, pp. 231-243.
No full textSynthesis, Characterization and X-ray Structure of [Pd(dppp)(h2O)(TsO)](TsO) (dppp = 1,3-bis(diphenylphosphino)propane; TsO = p-CH3C6H4SO3), a Catalytic species in CO-C2H4 Copolymerization
No full textInorganica Chimica Act
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