The structure of propadienone

Brown, R. D.; Champion, R.H.; Elmes, Patricia S.; Godfrey, Peter D.

doi:10.1021/ja00300a001

Cited by 48 publications

(16 citation statements)

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“…An orbital energy level diagram for PtC 3 is presented in Figure S1 in the Supporting Information. There are striking similarities between the geometries of MC 3 measured during the present work and that reported earlier for OC 3 by Brown et al [22] Applying the model of Pyykkç et al,P tCO,P tC,a nd Pt 2 C 3 are analogues of the well-known, stable oxocarbons carbon dioxide,monoxide,and suboxide,respectively,each of which have been known since the 19th century.Similarly,PtSi [23] can be regarded as an analogue of SiO.T he oxocarbon analogue of Pt 2 C 2 would be ethylene dione, [24] at ransient species characterized, only through spectroscopy,for the first time in 2015. This model can thus explain why PtCO,PtC,and PtC 3 , but not yet PtC 2 ,h ave been detected.…”

Section: 79898(4) Va Lues Of Vibrational Wavenumbers Calculated Asupporting

confidence: 88%

HIGHLY UNSATURATED PLATINUM AND PALLADIUM CARBENES PtC3 AND PdC3 ISOLATED AND CHARACTERIZED IN THE GAS PHASE

Bittner¹,

Zaleski²,

Tew³

et al. 2016

Proceedings of the 71st International Symposium on Molecular Spectroscopy

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Carbenes of platinum and palladium, PtC 3 and PdC 3 ,w ere generated in the gas phase through laser vaporization of ametal target in the presence of alow concentration of ahydrocarbon precursor undergoing supersonic expansion. Rotational spectroscopyand ab initio calculations confirm that both molecules are linear.The geometry of PtC 3 was accurately determined by fitting to the experimental moments of inertia of twenty-six isotopologues.T he results are consistent with the proposal of an autogenic isolobal relationship between O, Au + , and Pt atoms.

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Section: 79898(4) Va Lues Of Vibrational Wavenumbers Calculated Asupporting

confidence: 88%

HIGHLY UNSATURATED PLATINUM AND PALLADIUM CARBENES PtC3 AND PdC3 ISOLATED AND CHARACTERIZED IN THE GAS PHASE

Bittner¹,

Zaleski²,

Tew³

et al. 2016

Proceedings of the 71st International Symposium on Molecular Spectroscopy

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“…and acryloyl chloride (AC, 4 eq.) [14] at room temperature under Ar for 10 min, ltered, dried by rotavaper, redissolved in methylene chloride (MC), and precipitated in cold hexane. The nal product was ltered, dried, and stored in vacuo at room temperature.…”

Section: Synthesis and Characterization Of Hpegmentioning

confidence: 99%

Preparation of heterodifunctional polyethyleneglycols: Network formation, characterization, and cell culture analysis

Kao

Lok²,

Li³

2001

Journal of Biomaterials Science, Polymer Edition

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Polyethyleneglycols (PEG) are employed extensively in the development of biomaterials; however, the hydroxyl groups in PEG-diols have very limited chemical activity. We developed a synthesis scheme for a library of heterodifunctional PEG (hPEG) with two distinct terminal moieties to improve the reactivity and physicochemical properties of PEG. hPEG were employed in the formulation of polymer networks with various surface physicochemical properties and utilized to study cell-material interaction. Extensive NMR and HPLC analyses confirmed the chemical structure of hPEG. The hydrophilicity of the polymer network was predominantly dependent on the hPEG concentration with the molecular weight and terminal functional group playing lesser roles. Adherent human fibroblast density on the network remained constant with increasing hPEG concentration in the network formulation but decreased rapidly on networks containing 0.8-1.25 g ml(-1) of hPEG. This trend was independent of the hPEG terminal moiety and molecular weight. No adherent cell was observed on all films containing 2.5 g ml(-1) or more of hPEG.

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“…Note that the analogous propadienone (H 2 C=C=C=O) possesses a non-linear heavy-atom chain. 26 The free molecule shows a typical IR absorption band at 2289 cm À1 in a argon matrix. 27,28 After scaling the MP2/6-31G(d,p) harmonic vibrational wavenumbers by an average factor of 0.95, the calculated values are 114, 550, 552, 740, 1537, 2141 and 2366 cm…”

Section: Properties Of Carbon Suboxidementioning

confidence: 99%

Contrasting mechanism of the hydration of carbon suboxide and ketene. A theoretical study

Nguyen

Raspoet

Vanquickenborne

2000

J. Phys. Org. Chem.

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The protonation and hydration of carbon suboxide (O=C=C=C=O) were studied by ab initio molecular orbital methods. While the geometries of the stationary points were optimized using MP2/6-31G(d,p) calculations, relative energies were estimated using QCISD(T)/6-31G(d,p) and 6-311G(d,p) ZPE. The behaviour of carbon suboxide was compared with that of carbon dioxide and ketene. The protonation at the b-carbon is consistently favoured over that at the oxygen; the proton affinities (PA) are estimated to be PA(C 3 O 2 ) = 775 AE 15 and PA(H 2 CCO) = 820 AE 10 kJ mol À1 (experimental: 817 AE 3 kJ mol À1). The PAs at oxygen amount to 654, 641 and 542 kJ mol À1 (experimental: 548 kJ mol À1 ) for C 3 O 2 , H 2 CCO and CO 2 , respectively. Using the approach of one and two water molecules to model the hydration reaction, the calculated results consistently show that the addition of water across the C=O bond of ketene, giving a 1,1-ethenediol intermediate, is favoured over the C=C addition giving directly a carboxylic acid. A reverse situation occurs in carbon suboxide. In the latter, the energy barrier of the C=C addition is about 31 kJ mol À1 smaller than that of C=O addition. The C=C addition in C 3 O 2 is inherently favoured owing to a smaller energetic cost for the molecular distortion at the transition state, and a higher thermodynamic stability of the acid product. Molecular deformation of carbon suboxide is in fact a fairly facile process. A similar trend was observed for the addition of H 2 , HF and HCl on C 3 O 2 . In all three cases, the C=C addition is favoured, HCl having the lowest energy barrier amongst them. These preferential reaction mechanisms could be rationalized in terms of Fukui functions for both nucleophilic and electrophilic attacks.

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The structure of propadienone

Cited by 48 publications

References 0 publications

HIGHLY UNSATURATED PLATINUM AND PALLADIUM CARBENES PtC3 AND PdC3 ISOLATED AND CHARACTERIZED IN THE GAS PHASE

HIGHLY UNSATURATED PLATINUM AND PALLADIUM CARBENES PtC3 AND PdC3 ISOLATED AND CHARACTERIZED IN THE GAS PHASE

Preparation of heterodifunctional polyethyleneglycols: Network formation, characterization, and cell culture analysis

Contrasting mechanism of the hydration of carbon suboxide and ketene. A theoretical study

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