Boys interrupted : sex between men in post-Franco Spanish cinema.

The synthesis and characterization of a stable, acyclic two-coordinate silylene, Si­(SAr^Me₆)₂ [Ar^Me₆ = C₆H₃-2,6­(C₆H₂-2,4,6-Me₃)₂], by reduction of Br₂Si­(SAr^Me₆)₂ with a magnesium­(I) reductant is described. It features a V-shaped silicon coordination with a S–Si–S angle of 90.52(2)° and an average Si–S distance of 2.158(3) Å. Although it reacts readily with an alkyl halide, it does not react with hydrogen under ambient conditions, probably as a result of the ca. 4.3 eV energy difference between the frontier silicon lone pair and 3p orbitals

Mono- and bis-imidazolidinium ethynyl cations and the reduction of the latter to give an extended bis-1,4-([3]cumulene)-p-carbo-quinoid system

Sherpa Romeo yellow journal. This is the peer reviewed version. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsAn extended π-system containing two [3]cumulene fragments separated by a p-carbo-quinoid and stabilized by two capping N-heterocyclic carbenes (NHCs) has been prepared. Mono- and bis-imidazolidinium ethynyl cations have also been synthesized from the reaction of an NHC with phenylethynyl bromide or 1,4bis(bromoethynyl)benzene. Cyclic voltammetry coupled with synthetic and structural studies showed that the dication is readily reduced to a neutral, singlet bis-1,4-([3]cumulene)-p-carbo-quinoid due to the πaccepting properties of the capping NHCsYe

Do Extremely Bent Allenes Exist?

Bent allenes: Theoretical calculations show that extremely bent allenes, cyclic or acyclic, adopt a ground state that only bears a formal relationship to classical allenes. Consequently, five-membered ring allenes favor a carbene-like electronic structure and formally contain a trivalent carbon(II) center.peerReviewe

Pyrazolium- and 1,2-Cyclopentadiene-Based Ligands as σ-Donors: a Theoretical Study of Electronic Structure and Bonding

A high-level theoretical investigation of 1,2-cyclopentadiene (4) was performed using density functional theory and wave function methods. The results reveal that, in contrast to earlier assumptions, the ground state of this ephemeral “allene” is carbene-like with a small diradical component. Furthermore, the electronic structure and chemistry of 4 are found to parallel that of 1,2,4,6-cycloheptatetraene: both molecules possess a low-lying excited singlet state with a closed-shell carbenic structure, enabling rich coordination chemistry. Energy decomposition analyses conducted for currently unknown metal complexes of 4 as well as those involving stable carbenes based on the pyrazolium framework (aka “bent allenes” or remote N-heterocyclic carbenes) indicate that all investigated ligands form particularly strong metal–carbon bonds. Most notably, without exocyclic π-type substituents, 4 and pyrazolin-4-ylidenes are the strongest donor ligands examined, in large part because of the energy and shape of their highest occupied molecular orbital. As a whole, the current work opens a new chapter in the chemistry of 1,2-cyclopentadiene, which is hoped to spark renewed interest among experimentalists. In addition, results from the conducted bonding analyses underline that more emphasis should be placed on purely carbocyclic carbenes as unprecedented σ-donor strengths can be realized through this route.peerReviewe

Experimental and theoretical investigations of the redox behavior of the heterodichalcogenido ligands [((EPPr2)-Pr-i)((TePPr2)-Pr-i)N](-) (E = S, Se) : cyclic cations and acyclic dichalcogenide dimers

The two-electron oxidation of the lithium salts of the heterodichalcogenidoimidodiphosphinate anions [((EPPr2)-Pr-i)((TePPr2)-Pr-i)N](-) (1a, E = S; 1b, E = Se) with iodine yields cyclic cations [((EPPr2)-Pr-i)((TePPr2)-Pr-i)N](+) as their iodide salts [((SPPr2)-Pr-i)((TePPr2)-Pr-i)N]l (2a) and [((SePPr2)-Pr-i)((TePPr2)-Pr-i)N]l (2b). The five-membered rings in 2a and 2b both display an elongated E-Te bond as a consequence of an interaction between tellurium and the iodide anion. One-electron reduction of 2a and 2b with cobaltocene produces the neutral dimers ((EPPr2NPPr2Te)-Pr-i-Pr-i-)(2) (3a, E = S; 3b, E = Se), which are connected exclusively through a Te-Te bond. Two-electron reduction of 2a and 2b with 2 equiv of cobaltocene regenerates the corresponding dichalcogenidoimidodiphosphinate anions as ion-separated cobaltocenium salts Cp2Co[((EPPr2)-Pr-i)((TePPr2)-Pr-i)N] (4a, E = S; 4b, E = Se). The ditellurido analogue Cp2Co[((TePPr2)-Pr-i)(2)N] (4c) has been prepared in the same manner for comparison. Density functional theory calculations reveal that the preferential interaction of the iodide anion with tellurium is determined by the polarization of the lowest unoccupied molecular orbital [(sigma*(E-Te)] of the cations in 2a and 2b toward tellurium and that the formation of the dimers 3a and 3b with a central Te-Te linkage is energetically more favorable than the structural isomers with either E-Te or E-E bonds. Compounds 2a, 2b, 3a, 3b, 4a, 4b, and 4c have been characterized in solution by multinuclear NMR spectroscopy and in the solid state by X-ray crystallography

The Role of Orbital Symmetries in Enforcing Ferromagnetic Ground State in Mixed Radical Dimers

One of the first steps in designing ferromagnetic (FM) molecular materials of p-block radicals is the suppression of covalent radical–radical interactions that stabilize a diamagnetic ground state. In this contribution, we demonstrate that FM coupling between p-block radicals can be achieved by constructing mixed dimers from different radicals with differing symmetries of their singly occupied molecular orbitals. The applicability of this approach is demonstrated by studying magnetic interactions in organic radical dimers built from different derivatives of the well-known phenalenyl radical. The calculated enthalpies of dimerization for different homo- and heterodimers show that the formation of a mixed dimer with FM coupling is favored compared to the formation of homodimers with antiferromagenetic (AFM) coupling. We argue that cocrystallization of radicals with specifically tuned morphologies of their singly occupied molecular orbitals is a feasible and promising approach in designing new organic magnetic materials

Haptotropism in a Nickel Complex with a Neutral, π‐Bridging cyclo‐P4 Ligand Analogous to Cyclobutadiene

The reaction of ( 1 )Ni(η 2 -cod), 2 , incorporating a chelating bis( N -heterocyclic carbene) 1 , with P 4 in pentane yielded the dinuclear complex [( 2 )Ni] 2 (μ 2 ,η 2 :η 2 -P 4 ), 3 , formally featuring a cyclobutadiene-like, neutral, rectangular, π-bridging P 4 -ring. In toluene, the butterfly-shaped complex [( 1 )Ni] 2 (μ 2 ,η 2 :η 2 -P 2 ), 4 , with a formally neutral P 2 -unit was obtained from 2 and either P 4 or 3 . Computational studies showed that a low energy barrier haptotropic rearrangement involving two isomers of the μ 2 ,η 2 :η 2 -P 4 coordination mode and a low energy μ 2 ,η 4 :η 4 -P 4 coordination mode, as previously predicted for related nickel cyclobutadiene complexes, could explain the coalescence observed in the low temperature NMR spectra of 3 . The insertion of the ( 1 )Ni fragment into a P–P bond of P 7 (SiMe 3 ) 3 , forming complex 5 with a norbornane-like P 7 ligand, was also observed.peerReviewe