The equilibrium geometries, thermochemistry, and vibrational frequencies of the homoleptic binuclear rhenium carbonyls Re2(CO)n (n = 10, 9, 8, 7) were determined using the MPW1PW91 and BP86 methods from density functional theory (DFT) with the effective core potential basis sets LANL2DZ and SDD. In all cases triplet structures for Re2(CO)n were found to be unfavorable energetically relative to ...

Reliable thermochemistry is computed for infinite stretches of pure-carbon materials including acetylenic and cumulenic carbon chains, graphene sheet, and single-walled carbon nanotubes (SWCNTs) by connection to the properties of finite size molecules that grow into the infinitely long systems. Using ab initio G3 theory, the infinite cumulenic chain (:C[double bond]C[double bond]C[double bond]C...

We have studied the wavelength dependence for the photoreversal of a monoadducted psoralen derivative, HMT [4'-(hydroxymethyl)-4,5',8-trimethylpsoralen], in a single-stranded deoxyoligonucleotide (5'-GAAGCTACGAGC-3'). The psoralen was covalently attached to the thymidine residue in the oligonucleotide as either a furan-side monoadduct, which is formed through the cycloaddition between the 4',5'...

The metalation reactions between [Pt2(4-MeC6H4)4(μ-SEt2)2] and 2-X,6-FC6H3CH[double bond, length as m-dash]NCH2CH2NMe2 (X = Br, Cl) have been studied. In all cases, seven-membered platinacycles are formed in a process that involves an initial reductive elimination from cyclometallated Pt(IV) intermediate compounds, [PtX(4-CH3C6H4)2(ArCH[double bond, length as m-dash]NCH2CH2NMe2)] (X = Br, Cl), ...

A simple, fast approach elucidated carbon-carbon double bond positions in unsaturated lipids. Lipids were deposited onto various surfaces and the products from their oxidation in ambient air were observed by electrospray ionization (ESI) mass spectrometry (MS). The most common oxidative products, aldehydes, were detected as transformations at the cleaved double bond positions. Ozonides and carb...

X-ray structure determination of the enamine (Z)-4-(6'-t-butoxycarbonyl-2',2'-dimethyl-5'-phenyl3'-hexen-3'-yl)morpholine (1) reveals that certain bulky groups may enforce a relative orientation of the molecular subunits without conjugative interaction between the nitrogen lone pair and the olefinic double bond. According to the results of quantum chemical ab initio calculations the experimenta...

In the title salt, C15H36N6 (2+)·2C24H20B(-), the three N-C bond lengths in the central C3N unit of the bis-amidinium ion range between 1.388 (3) and 1.506 (3) Å, indicating single- and double-bond character. Furthermore, four C-N bonds have double-bond character. Here, the bond lengths range from 1.319 (3) to 1.333 (3) Å. Delocalization of the positive charges occurs in the N/C/N and C/N/C pla...

Vinylidene complexes [Ru(η(5)-C5H5){[double bond, length as m-dash]C[double bond, length as m-dash]C(H)R}(PPh3)L]BPh4 (, ) [L = P(OMe)3, P(OEt)3; R = Ph, p-tolyl, Bu(t), H] react with hydrazine R1NHNH2 (R1 = H, Me, Ph) to afford nitrile derivatives [Ru(η(5)-C5H5)(N[triple bond, length as m-dash]CCH2R)(PPh3)L]BPh4 (, ) and amine R1NH2. Hydroxylamine NH2OH also reacts with vinylidenes , to yield ...

In the title solvated salt, C7H16NO(+)·C24H20B(-)·C2H3N, the C-N bond lengths in the cation are 1.2831 (19), 1.467 (2) and 1.465 (2) Å, indicating double- and single-bond character, respectively. The C-O bond length of 1.2950 (18) Å shows a double-bond character, pointing towards charge delocalization within the NCO plane of the iminium ion. The two C atoms of the n-butyl group are disordered o...

Full geometric optimization of tricyclo[4.2.2.02,5]deca-3,7-diene (TDD) has been done by DFT/B3LYP methods and the structure of the molecule was investigated. Cyclobuten double bond (I) of molecule is syn pyramidalized, and bicyclookten double bond (II) is also exo pyramidalized. The double bond (I) is more pyramidalized than the double bond (II) and it has higher reactivity. The TDD-Br2 system...