Tag: M.W:400-500

Children learn through play, and they learn more than adults might expect. Science experiments are a great way to spark their curiosity, get their minds active, and encourage them to do something that doesn’t involve a screen. 19845-69-3, C30H32P2. A document type is Article, introducing its new discovery., Formula: C30H32P2

Preparation, characterization, and luminescence properties of a 58-electron linear Pt4 cluster, [Pt4(dmb)4(PPh3)2]2+ (dmb = 1,8-diisocyano-p-menthane), and its diphosphine polymers

The title compounds [Pt4(dmb)4(PPh3)2]Cl2 (1) and {[Pt4(dmb)4(diphos)]Cl2}n (diphos = dppb (2), dppp (3), dpph (4)) have been prepared in good yields from the reaction of Pt2(dba)3·CHCl3 with 2 equiv of dmb and 1 equiv of PPh3 for 1 (dba = dibenzylideneacetone) and from the reactions of Pt2(dba)3·CHCl3 with 2 equiv of dmb and 0.5 equiv of diphos for 2-4. The structure for 1 consists of a quasi-linear Pt4L22+ species (L = PPh3; d(PtPt) = 2.666(2), 2.655(2), 2.641(2) A), where the dmb ligands bridge the Pt atoms forming a catenate. From Raman spectroscopy, the two v(PtPt) active modes for 1 are observed at 162 and 84 cm-1 (F(PtPt) = 2.36 mdyn A-1). For 2-4, the diphos ligands induce the formation of amorphous polymeric materials (X-ray powder diffraction patterns) with MW ranging from 84 000 to 307 000 according to viscometry. EHMO calculations predict that the HOMO and LUMO are the two dsigma* orbitals arising from four interacting Pt atoms via the dx2-y2, dz2, s, and px M atomic orbitals. These are mixed with the ddelta and CNR(pi*) MO’s. From the examination of the position, absorptivity, and fwhm (full width at half maximum) of the strongly allowed low-energy UV-vis band, a dsigma* ? dsigma* assignment is made (lambdamax = 405 nm, ? = 35 800 M-1 cm-1; EtOH for 1). The four compounds are luminescent at 77 K in EtOH, where lambdaemi are 750, 736, 750, and 755 nm and taue are 2.71, 4.78, 5.15, and 5.17 ns for 1-4, respectively. On the basis of the Stokes shifts (10 000-12 000 cm-1) and the long emission lifetimes, a phosphorescence dsigma* ? dsigma* assignment is made for the observed emissions. Crystal data for 1: crystal system triclinic; space group P1; a = 12.624(4) A;b = 14.24(2) A; c = 27.312(3) A; alpha = 92.35(3); beta= 91.655(15); gamma = 90.28(5); V = 4903(7) A3; Z = 2; Dcalc = 1.528 g cm-3; R1 = 0.0738; wR2 = 0.2097; S = 1.018.

Interested yet? Keep reading other articles of 19845-69-3!, Formula: C30H32P2

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

657408-07-6, Name is Dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphine, molecular formula is C26H35O2P, belongs to chiral-phosphine-ligands compound, is a common compound. In a patnet, once mentioned the new application about 657408-07-6, name: Dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphine

A catalytic route to dibenzodiazepines involving Buchwald-Hartwig coupling: Reaction scope and mechanistic consideration

We report a new synthetic method for the synthesis of a family of dibenzodiazepines (DBDAs), employing Pd-catalyzed C-N coupling of o-bromoaldimine, with o-bromoaniline as the key step. Eleven DBDAs were prepared, containing electron-withdrawing groups (CN, F, NO2) and electron-donating groups (OMe). The reaction conditions were optimized (catalyst, phosphine, base and solvent) and best results were obtained with Pd(OAc)2, SPhos, Cs2CO3 in THF. Due to the ambiguity of the mechanism at hand, various mechanistic studies were performed, that included DFT calculations. The oxidative addition process was studied in detail by DFT, and these studies supported the observed reaction regioselectivity. The adducts formed between the aldimine and the Pd(0) catalyst were calculated to be more stable than the ones formed with the amine, and the barrier for the oxidative addition at the C-Br bond of the aldimine was calculated to be lower than the one at the C-Br bond of the aryl amine. The formation of DBDA over the dibenzoaminopiperidine has been explained in the final cyclization step.

Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.name: Dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphine. In my other articles, you can also check out more blogs about 657408-07-6

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.564483-19-8, Name is Di-tert-butyl(2′,4′,6′-triisopropyl-[1,1′-biphenyl]-2-yl)phosphine, molecular formula is C29H45P. In a Article，once mentioned of 564483-19-8, Computed Properties of C29H45P

Catalytic Activity of Cationic and Neutral Silver(I)-XPhos Complexes with Nitrogen Ligands or Tolylsulfonate for Mannich and Aza-Diels-Alder Coupling Reactions

Cationic and neutral silver(I)-L complexes (L=Buchwald-type biaryl phosphanes) with nitrogen co-ligands or organosulfonate counter ions have been synthesised and characterised through their structural and spectroscopic properties. At room temperature, both cationic and neutral silver(I)-L complexes are extremely active catalysts in the promotion of the single and double A3 coupling of terminal (di)alkynes, pyrrolidine and formaldehyde. In addition, the aza-Diels-Alder two- and three-component coupling reactions of Danishefsky’s diene with an imine or amine and aldehyde are efficiently catalysed by these cationic or neutral silver(I)-L complexes. The solvent influences the catalytic performance due to limited complex solubility or solvent decomposition and reactivity. The isolation of new silver(I)-L complexes with reagents as ligands lends support to mechanistic proposals for such catalytic processes. The activity, stability and metal-distal arene interaction of these silver(I)-L catalysts have been compared with those of analogous cationic gold(I) and copper(I) complexes.

Note that a catalyst decreases the activation energy for both the forward and the reverse reactions and hence accelerates both the forward and the reverse reactions.Computed Properties of C29H45P, you can also check out more blogs about564483-19-8

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

A catalyst don’t appear in the overall stoichiometry of the reaction it catalyzes, but it must appear in at least one of the elementary reactions in the mechanism for the catalyzed reaction. 657408-07-6, Name is Dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphine, molecular formula is C26H35O2P. In a Article，once mentioned of 657408-07-6, Product Details of 657408-07-6

Atropselective syntheses of (-) and (+) rugulotrosin A utilizing point-to-axial chirality transfer

Chiral, dimeric natural products containing complex structures and interesting biological properties have inspired chemists and biologists for decades. A seven-step total synthesis of the axially chiral, dimeric tetrahydroxanthone natural product rugulotrosin A is described. The synthesis employs a one-pot Suzuki coupling/dimerization to generate the requisite 2,2?-biaryl linkage. Highly selective point-to-axial chirality transfer was achieved using palladium catalysis with achiral phosphine ligands. Single X-ray crystal diffraction data were obtained to confirm both the atropisomeric configuration and absolute stereochemistry of rugulotrosin A. Computational studies are described to rationalize the atropselectivity observed in the key dimerization step. Comparison of the crude fungal extract with synthetic rugulotrosin A and its atropisomer verified that nature generates a single atropisomer of the natural product.

Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data.Product Details of 657408-07-6, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 657408-07-6, in my other articles.

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.564483-18-7, Name is 2-(Dicyclohexylphosphino)-2′,4′,6′-tri-i-propyl-1,1′-biphenyl, molecular formula is C33H49P. In a Article，once mentioned of 564483-18-7, Recommanded Product: 2-(Dicyclohexylphosphino)-2′,4′,6′-tri-i-propyl-1,1′-biphenyl

Ruthenium-catalyzed hydroarylation of methylenecyclopropanes through C-H bond cleavage: Scope and mechanism

Intermolecular hydroarylation reactions of highly strained methylenecyclopropanes 2-phenylmethylenecyclopropane (1), 2,2- diphenylmethylenecyclopropane (2), methylenespiropentane (3), bicyclopropylidene (4), (dicyclopropylmethylene)cyclopropane (5), and benzhydrylidenecyclopropane (6) through C-H bond functionalization of 2-phenylpyridine (7 a) and other arenes with directing groups were studied. The reaction was very sensitive to the substitution on the methylenecyclopropanes. Although these transformations involved (cyclopropylcarbinyl)-metal intermediates, substrates 1 and 4 furnished anti-Markovnikov hydroarylation products with complete conservation of all cyclopropane rings in 11-93 % yield, whereas starting materials 3 and 5 were inert toward hydroarylation. Methylenecyclopropane 6 formed the products of formal hydroarylation reactions of the longest distal C-C bond in the methylenecyclopropane moiety in high yield, and hydrocarbon 2 afforded mixtures of hydroarylated products in low yields with a predominance of compounds that retained the cyclopropane unit. As byproducts, Diels-Alder cycloadducts and self-reorganization products were obtained in several cases from substrates 1-3 and 5. The structures of the most important new products have been unambiguously determined by X-ray diffraction analyses. On the basis of the results of hydroarylation experiments with isotopically labeled 7 a-[D5], a plausible mechanistic rationale and a catalytic cycle for these unusual ruthenium-catalyzed hydroarylation reactions have been proposed. Arene-tethered ruthenium-phosphane complex 53, either isolated from the reaction mixture or independently prepared, did not show any catalytic activity. Copyright

Note that a catalyst decreases the activation energy for both the forward and the reverse reactions and hence accelerates both the forward and the reverse reactions.Recommanded Product: 2-(Dicyclohexylphosphino)-2′,4′,6′-tri-i-propyl-1,1′-biphenyl, you can also check out more blogs about564483-18-7

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Electric Literature of 13991-08-7. Chemistry is an experimental science, and the best way to enjoy it and learn about it is performing experiments.Introducing a new discovery about 13991-08-7, Name is 1,2-Bis(diphenylphosphino)benzene

Rhodium-catalyzed addition-spirocyclization of arylboronic esters containing beta-aryl alpha,beta-unsaturated ester Moiety

Abstract In this study, we developed a rhodium(I)-catalyzed spiro-cyclization. The reaction includes 1,4-rhodium migration and provides a route for forming spirocyclic 1-indanones.

If you are hungry for even more, make sure to check my other article about 13991-08-7. Electric Literature of 13991-08-7

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Related Products of 19845-69-3, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 19845-69-3, Name is 1,6-Bis(diphenylphosphino)hexane, molecular formula is C30H32P2. In a Article，once mentioned of 19845-69-3

The Heteronuclear Cluster Chemistry of the Group 1 B Metals. Part 11. Effect of the Nature of the Bidentate Diphosphine Ligand on the Metal Framework Structures of the Gold Heteronuclear Cluster Compounds (n = 1-6). X-Ray Crystal Stru…

Treatment of acetone solutions of the salt 2 with a dichloromethane solution of the appropriate complex (n = 1-6), in the presence of TlPF6, affords the mixed-metal cluster compounds in ca. 60-70percent yield.X-Ray diffraction studies on (2) and (3) reveal that the formal replacement of the two PPh3 ligands attached to the Au atoms in (1) by Ph2P(CH2)nPPh2 (n = 1 or 2) alters the capped trigonal-bipyramidal skeletal geometry adopted by (1).The cluster (2) crystallizes in two forms, monoclinic and orthorhombic, but X-ray diffraction studies on both forms show that the molecular structures adopted by (2) are closely similar in each case.The metal core of (2) consists of a square-based pyramid, defined by two Au atoms in the basal plane and a Ru atom at the apex, with the Ru3 face of this Au2Ru3 unit capped by a Ru atom .The Ph2PCH2PPh2 ligand bridges the two Au atoms, one hydrido ligand caps a Ru3 face and one bridges a Ru-Ru edge of the metal framework, and each Ru atoms is ligated by three terminal CO groups.The skeletal geometry of (3) is reasonably similar to that exhibited by (1), but one of the Au-Ru distances <3.446(4) Angstroem> is too long for any significant bonding interaction between the two atoms.Thus, the metal framework of (3) is somewhat distorted towards a capped square-based pyramid .Variable-temperature 1H and 31P-(1H) n.m.r. studies show that, at ambient temperature in solution, the metal cores of (3)-(7) all undergo dynamic behaviour involving gold atom site exchange.

The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 19845-69-3 is helpful to your research., Related Products of 19845-69-3

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Related Products of 1034-39-5, Children learn through play, and they learn more than adults might expect. Science experiments are a great way to spark their curiosity, get their minds active, and encourage them to do something that doesn’t involve a screen. 1034-39-5, C18H15Br2P. A document type is Article, introducing its new discovery.

Oxidation in Nonclassical Organolanthanide Chemistry: Synthesis, Characterization, and X-ray Crystal Structures of Cerium(III) and -(IV) Amides

[Ce(NR2)3] (R = SiMe3) with TeCl 4 in tetrahydrofuran solution gave a mixture of two major products in a combined yield of ca. 50% based on available metal: (i) the Ce(IV) amide [CeCl(NR2)3] (1), which was isolated as purple needles and identified on the basis of 1H NMR and mass spectra, microanalysis, and a single-crystal X-ray analysis [C18H 54CeClN3Si6, rhombohedral, R3c (No. 161), a = b = 18.4508(7) A, c = 16.8934(7) A, Z = 6]; (ii) unstable [{Ce(NR2)2(mu-Cl)(thf)}2] (2), as colorless blocks [C32H88Ce2Cl2N 4O2Si8, monoclinic, P21/n (No. 14), a = 14.506(3) A, b = 13.065(3) A, c = 16.779(3) A, beta = 113.789(12) A, Z = 2], which readily disproportionated in solution. In toluene solution, the product 1 was obtained exclusively. The same cerium(III) amide starting material was oxidized by PBr2Ph 3 in diethyl ether solution to give purple [CeBr(NR2) 3] (3) [C18H54BrCeN3Si6, rhombohedral, R3c (No. 161), a = b = 18.4113(12) A, c = 16.9631(17) A, Z = 6], along with presumed [CeBr3(OEt2) n], which has not been characterized but with thf, by displacement of the ether ligands, gave [CeBr3(thf)4] (4) [C 16H32Br3CeO4, triclinic, P1 (No. 2), a = 8.2536(7) A, b = 9.4157(5) A, c = 15.5935(14) A, alpha = 79.009(5), beta = 87.290(3), gamma = 74.835(5), Z = 2). TeBr4 reacted with [Ce(NR2)3] in thf to give small amounts of 3; the major product (although only formed in 15% yield) was monomeric [CeBr2(NR2)(thf)3] (5) [C 18H42Br2CeNO3Si2, monoclinic, P21/c (No. 14), a = 14.9421(4) A, b = 11.8134(5) A, c = 15.8317(7) A, alpha = gamma = 120, beta = 92.185(3), Z = 4].

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Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

13991-08-7, Name is 1,2-Bis(diphenylphosphino)benzene, molecular formula is C30H24P2, belongs to chiral-phosphine-ligands compound, is a common compound. In a patnet, once mentioned the new application about 13991-08-7, Product Details of 13991-08-7

Carbon-bridged diphosphine ligands for chromium-catalysed ethylene tetramerisation and trimerisation reactions

The use of carbon-bridged diphosphine ligands in chromium-catalysed ethylene tri- and tetramerisation reactions has been investigated. Two- and three-carbon spacer ligands all showed activity for selective oligomerisation, with a structure-selectivity correlation between P-Cr-P bite angle and 1-octene:1-hexene ratio evident. Activated chromium complexes of single carbon spacer diphosphines were also shown to be effective tetramerisation catalysts, provided that the ligand is innocent under the conditions of catalyst activation. A catalyst with the bis(diphenylphosphino)benzene ligand was found to be exceptionally active, although the combined 1-hexene and 1-octene selectivity was lower than with the best diphosphinoamine (PNP) ligands. The yield losses to by-products can to an extent be minimised by the use of high reaction temperatures and pressures. Unlike with the PNP-based systems, attempts to activate the Cr/bis(diphenylphosphino)benzene catalyst in situ from a chromium salt and free ligand resulted in low activity and high polymer formation. The effect of different phosphine substitution on catalyst selectivity was explored. Steric constraints around the catalytic centre (ortho-alkylphenyl phosphines) resulted in a shift towards 1-hexene formation, as with PNP catalysts. Additionally, the basicity of the phosphines appears to influence catalyst selectivity, with alkyl phosphines favouring trimerisation. An interplay between phosphine basicity and bridge structure is in evidence, however, as a catalyst containing a ligand with both basic phosphine atoms and a small bite angle was shown to be selective towards 1-octene.

Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.Product Details of 13991-08-7. In my other articles, you can also check out more blogs about 13991-08-7

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

A catalyst don’t appear in the overall stoichiometry of the reaction it catalyzes, but it must appear in at least one of the elementary reactions in the mechanism for the catalyzed reaction. 13991-08-7, Name is 1,2-Bis(diphenylphosphino)benzene, molecular formula is C30H24P2. In a Article，once mentioned of 13991-08-7, Formula: C30H24P2

Octahedral Alkylidyne Complexes of Tungsten with Chelating Ligands as Precursors for Polynuclear Compounds. Crystal Structures of CR)(CO)2(dmpe)(NCS) and (R= C6H4Me-4, dmpe = Me2PCH2CH2PMe2)

The tungsten carbyne complexes CR)(CO)2(L-L)X> (R=C6H4Me-4) where L-L = 2,2′-bipyridine (bipy), 1,2-bis(dimethylphosphino)ethane (dmpe), or 1,2-bis(diphenylphosphino)benzene (dppb), and X = Cl, Br, or NCS have been prepared and the structure of the N-bonded thiocyanate derivative CR)(CO)2(dmpe)(NCS)> determined by X-ray diffraction.The reaction of the octahedral carbynes with (tht = tetrahydrothiophene) gave the dimetallic species , when X<*>Cl are mixtures due to an interchange of X and Cl between the Au and W.The carbynes also reacted with to give , which for X = NCS are mixtures of two isomeric forms.The carbynes containing dmpe reacted with to give the trimetallic clusters (X = Cl or Br) which in solution exist as a mixture of interconverting isomers.The X-ray crystal structure determination of the bromo derivative revealed that, in the solid, the stereochemistry of the W(CO)2(dmpe)X fragment is different from that corresponding to the starting carbyne.The dmpe carbynes also reacted with in toluene to afford the bimetallic compounds (X = Cl or Br) having a Fe(CO)4 fragment co-ordinated to the W<*>CR bond.

Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data.Formula: C30H24P2, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 13991-08-7, in my other articles.

Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate