Tetrahedrane—Dossier of an Unknown

Abstract

To probe whether tetrahedrane should be isolable the thermodynamics and kinetics of C4H4 singlet and triplet structures were studied extensively at the CCSD(T)/cc-pVTZ//CCSD(T)/cc-pVDZ, CCSD(T)/cc-pVDZ, CCSD(T)/cc-pVDZ//B3 LYP/6-311G**, and B3 LYP/6-311G** levels of theory. The reaction of cyclopropene with atomic carbon, which was previously suggested to involve tetrahedrane as a reactive intermediate, was re-examined experimentally with low-temperature matrix-isolation techniques. While experimental and theoretical results exclude the intermediacy of tetrahedrane in the above reaction, it is predicted to be an isolable molecule. Among the many C4H4 species, we pay special attention to the electronic effects on the ground state multiplicity of the respective carbenes.

Di‐tert‐butyldiphosphatetrahedrane: Catalytic Synthesis of the Elusive Phosphaalkyne Dimer

“…Abstract: While tetrahedranes as af amily are scarce,n eutral heteroatomic species are all but unknown, with the only reported example being AsP 3 .Herein, we describe the isolation of aneutral heteroatomic X 2 Y 2 molecular tetrahedron (X, Y = p-block elements), whicha lso is the long-sought-after free phosphaalkyne dimer.D i-tert-butyldiphosphatetrahedrane, (tBuCP) 2 ,i sf ormed from the monomer tBuCP in an ickelcatalyzedd imerization reaction using [(NHC)Ni(CO) 3 ] (NHC = 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (IMes) and 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene (IPr)). Single-crystal X-ray structure determination of as ilver(I) complex confirms the structure of (tBuCP) 2 .T he influence of the N-heterocyclic carbene ligand on the catalytic reaction was investigated, and am echanism was elucidated using ac ombination of synthetic and kinetic studies and quantum chemical calculations.…”

“…Single-crystal X-ray structure determination of as ilver(I) complex confirms the structure of (tBuCP) 2 .T he influence of the N-heterocyclic carbene ligand on the catalytic reaction was investigated, and am echanism was elucidated using ac ombination of synthetic and kinetic studies and quantum chemical calculations.Tetrahedranes (tricyclo[1.1.0.0 2, 4 ]butanes) have considerable practical and theoretical significance because of their high energy content, large bond strain and ensuing high reactivity. [1] While theoretical chemists have endeavored to determine the electronic structure and the thermodynamic stability of tetrahedranes with ever increasing accuracy, [2][3][4][5] synthetic chemists have striven to develop effective protocols for their preparation. Thei solation by Maier and co-workers of the first organic tetrahedrane,(tBuC) 4 ,was amilestone in organic synthesis (Figure 1a).…”

Topochemical Transformations of CaX2 (X=C, Si, Ge) to Form Free‐Standing Two‐Dimensional Materials

“…[34] In this context,itisworthwhile to mention that based on DFT calculations, Schreiner has predicted that unsubstituted tetrahedrane is kinetically stable. [35] Clearly, within the cubic lattice of Ca II ions, free C 4 4À is stabilized, albeit as ah igh-pressurep hase. Our computations show that this cubic phase of CaC 2 is 105 kcal mol À1 higher in energy than the tetragonal/monoclinic phase with isolatedC 2 2À units.…”

Di‐tert‐butyldiphosphatetrahedran: Katalytische Synthese des freien Phosphaalkin‐Dimers

“…Tetrahedrane (Tricyclo[1.1.0.0 2, 4 ]butane) sind aufgrund ihres hohen Energiegehalts, der großen Bindungsspannung und der folglich hohen Reaktivität von beträchtlicher theoretischer und praktischer Bedeutung . In theoretischen Studien wurde die elektronische Struktur und die thermodynamische Stabilität von Tetrahedranen mit zunehmender Genauigkeit berechnet . Darüber hinaus waren synthetische Chemiker bestrebt, effektive Synthesemethoden für die Darstellung dieser Moleküle zu entwickeln.…”