Tetrahedrane

Last updated
Tetrahedrane
Tetrahedrane-3D-balls.png
Names
Preferred IUPAC name
Tricyclo[1.1.0.02,4]butane
Identifiers
3D model (JSmol)
2035811
ChEBI
ChemSpider
PubChem CID
  • InChI=1S/C4H4/c1-2-3(1)4(1)2/h1-4H Yes check.svgY
    Key: FJGIHZCEZAZPSP-UHFFFAOYSA-N Yes check.svgY
  • C12C3C1C23
Properties
C4H4
Molar mass 52.076 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Tetrahedrane is a hypothetical platonic hydrocarbon with chemical formula C4H4 and a tetrahedral structure. The molecule would be subject to considerable angle strain and has not been synthesized as of 2023. However, a number of derivatives have been prepared. In a more general sense, the term tetrahedranes is used to describe a class of molecules and ions with related structure, e.g. white phosphorus.

Contents

Organic tetrahedranes

In 1978, Günther Maier prepared tetra-tert-butyl-tetrahedrane. [1] The bulky tert-butyl (t-Bu) substituents envelop the tetrahedrane core. Maier suggested that bonds in the core are prevented from breaking because this would force the substituents closer together (corset effect) resulting in Van der Waals strain. Tetrahedrane is one of the possible platonic hydrocarbons and has the IUPAC name tricyclo[1.1.0.02,4]butane.

Unsubstituted tetrahedrane (C4H4) remains elusive, although it is predicted to be kinetically stable. One strategy that has been explored (but thus far failed) is reaction of propene with atomic carbon. [2] Locking away a tetrahedrane molecule inside a fullerene has only been attempted in silico . [3] Due to its bond strain and stoichiometry, tetranitrotetrahedrane has potential as a high-performance energetic material (explosive). [4] Some properties have been calculated based on quantum chemical methods. [5]

Tetra-tert-butyltetrahedrane

This compound was first synthesised starting from a cycloaddition of an alkyne with t-Bu substituted maleic anhydride, [6] followed by rearrangement with carbon dioxide expulsion to a cyclopentadienone and its bromination, followed by addition of the fourth t-Bu group. Photochemical cheletropic elimination of carbon monoxide of the cyclopentadienone gives the target. Heating tetra-tert-butyltetrahedrane gives tetra-tert-butylcyclobutadiene. Though the synthesis appears short and simple, by Maier's own account, it took several years of careful observation and optimization to develop the correct conditions for the challenging reactions to take place. For instance, the synthesis of tetrakis(t-butyl)cyclopentadienone from the tris(t-butyl)bromocyclopentadienone (itself synthesized with much difficulty) required over 50 attempts before working conditions could be found. [7] The synthesis was described as requiring "astonishing persistence and experimental skill" in one retrospective of the work. [8] In a classic reference work on stereochemistry, the authors remark that "the relatively straightforward scheme shown [...] conceals both the limited availability of the starting material and the enormous amount of work required in establishing the proper conditions for each step." [9]

Tetra-tert-butyl-tetrahedrane synthesis 1978 Tetra-tert-butyl-tetrahedrane synthesis.svg
Tetra-tert-butyl-tetrahedrane synthesis 1978

Eventually, a more scalable synthesis was conceived, in which the last step was the photolysis of a cyclopropenyl-substituted diazomethane, which affords the desired product through the intermediacy of tetrakis(tert-butyl)cyclobutadiene: [10] [11] This approach took advantage of the observation that the tetrahedrane and the cyclobutadiene could be interconverted (uv irradiation in the forward direction, heat in the reverse direction).

Tetra-tert-butyl-tetrahedrane synthesis 1991 Tetrahedrane from diazo.png
Tetra-tert-butyl-tetrahedrane synthesis 1991


Tetrakis(trimethylsilyl)tetrahedrane

Tetrakis(trimethylsilyl)tetrahedrane is relatively stable TMS-tetrahedrane-3D-vdW.png
Tetrakis(trimethylsilyl)tetrahedrane is relatively stable

Tetrakis(trimethylsilyl)tetrahedrane can be prepared by treatment of the cyclobutadiene precursor with tris(pentafluorophenyl)borane [12] and is far more stable than the tert-butyl analogue. The silicon–carbon bond is longer than a carbon–carbon bond, and therefore the corset effect is reduced. [13] Whereas the tert-butyl tetrahedrane melts at 135  °C concomitant with rearrangement to the cyclobutadiene, tetrakis(trimethylsilyl)tetrahedrane, which melts at 202 °C, is stable up to 300 °C, at which point it cracks to bis(trimethylsilyl)acetylene.

The tetrahedrane skeleton is made up of banana bonds, and hence the carbon atoms are high in s-orbital character. From NMR, sp-hybridization can be deduced, normally reserved for triple bonds. As a consequence the bond lengths are unusually short with 152 picometers.

Reaction with methyllithium with tetrakis(trimethylsilyl)tetrahedrane yields tetrahedranyllithium. [14] Coupling reactions with this lithium compound gives extended structures. [15] [16] [17]

A bis(tetrahedrane) has also been reported. [18] The connecting bond is even shorter with 143.6 pm. An ordinary carbon–carbon bond has a length of 154 pm.

Synthesis of tetrakis(trimethylsilyl)tetrahedrane and its dimer. Tetratrimethylsilyltetrahedrane.svg
Synthesis of tetrakis(trimethylsilyl)tetrahedrane and its dimer.

Tetrahedranes with non-carbon cores

In tetrasilatetrahedrane features a core of four silicon atoms. The standard silicon–silicon bond is much longer (235 pm) and the cage is again enveloped by a total of 16 trimethylsilyl groups, which confer stability. The silatetrahedrane can be reduced with potassium graphite to the tetrasilatetrahedranide potassium derivative. In this compound one of the silicon atoms of the cage has lost a silyl substituent and carries a negative charge. The potassium cation can be sequestered by a crown ether, and in the resulting complex potassium and the silyl anion are separated by a distance of 885 pm. One of the Si−–Si bonds is now 272 pm and the tetravalent silicon atom of that bond has an inverted tetrahedral geometry. Furthermore, the four cage silicon atoms are equivalent on the NMR timescale due to migrations of the silyl substituents over the cage. [19]

Tetrasilatetrahedrane Tetrasilatetrahedrane.png
Tetrasilatetrahedrane

The dimerization reaction observed for the carbon tetrahedrane compound is also attempted for a tetrasilatetrahedrane. [20] In this tetrahedrane the cage is protected by four so-called supersilyl groups in which a silicon atom has 3 tert-butyl substituents. The dimer does not materialize but a reaction with iodine in benzene followed by reaction with the tri-tert-butylsilaanion results in the formation of an eight-membered silicon cluster compound which can be described as a Si2 dumbbell (length 229 pm and with inversion of tetrahedral geometry) sandwiched between two almost-parallel Si3 rings.

Silicon cluster compound SilatetrahedraneDimer.png
Silicon cluster compound

In eight-membered clusters of in the same carbon group, tin Sn8R6 and germanium Ge8R6 the cluster atoms are located on the corners of a cube.

Inorganic and organometallic tetrahedranes

Structure of [InC(tms)3]4, a tetrahedrane with an In4 core (dark gray = In, orange = Si). YUZZOI.svg
Structure of [InC(tms)3]4, a tetrahedrane with an In4 core (dark gray = In, orange = Si).
Metal clusters that have tetrahedral cores are often called tetrahedranes. TetrahedraneClusters.png
Metal clusters that have tetrahedral cores are often called tetrahedranes.

The tetrahedrane motif occurs broadly in chemistry. White phosphorus (P4) and yellow arsenic (As4) are examples. Several metal carbonyl clusters are referred to as tetrahedranes, e.g. tetrarhodium dodecacarbonyl.

Metallatetrahedranes with a single metal (or phosphorus atom) capping a cyclopropyl trianion also exist. [22]

See also

Related Research Articles

<span class="mw-page-title-main">Sharpless epoxidation</span> Chemical reaction

The Sharpless epoxidation reaction is an enantioselective chemical reaction to prepare 2,3-epoxyalcohols from primary and secondary allylic alcohols. The oxidizing agent is tert-butyl hydroperoxide. The method relies on a catalyst formed from titanium tetra(isopropoxide) and diethyl tartrate.

Cubane is a synthetic hydrocarbon compound with the formula C8H8. It consists of eight carbon atoms arranged at the corners of a cube, with one hydrogen atom attached to each carbon atom. A solid crystalline substance, cubane is one of the Platonic hydrocarbons and a member of the prismanes. It was first synthesized in 1964 by Philip Eaton and Thomas Cole. Before this work, Eaton believed that cubane would be impossible to synthesize due to the "required 90 degree bond angles". The cubic shape requires the carbon atoms to adopt an unusually sharp 90° bonding angle, which would be highly strained as compared to the 109.45° angle of a tetrahedral carbon. Once formed, cubane is quite kinetically stable, due to a lack of readily available decomposition paths. It is the simplest hydrocarbon with octahedral symmetry.

<span class="mw-page-title-main">Organolithium reagent</span> Chemical compounds containing C–Li bonds

In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers. They have also been applied in asymmetric synthesis in the pharmaceutical industry. Due to the large difference in electronegativity between the carbon atom and the lithium atom, the C−Li bond is highly ionic. Owing to the polar nature of the C−Li bond, organolithium reagents are good nucleophiles and strong bases. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes pyrophoric.

<span class="mw-page-title-main">Cyclobutadiene</span> Chemical compound

Cyclobutadiene is an organic compound with the formula C4H4. It is very reactive owing to its tendency to dimerize. Although the parent compound has not been isolated, some substituted derivatives are robust and a single molecule of cyclobutadiene is quite stable. Since the compound degrades by a bimolecular process, the species can be observed by matrix isolation techniques at temperatures below 35 K. It is thought to adopt a rectangular structure.

The Heck reaction is the chemical reaction of an unsaturated halide with an alkene in the presence of a base and a palladium catalyst to form a substituted alkene. It is named after Tsutomu Mizoroki and Richard F. Heck. Heck was awarded the 2010 Nobel Prize in Chemistry, which he shared with Ei-ichi Negishi and Akira Suzuki, for the discovery and development of this reaction. This reaction was the first example of a carbon-carbon bond-forming reaction that followed a Pd(0)/Pd(II) catalytic cycle, the same catalytic cycle that is seen in other Pd(0)-catalyzed cross-coupling reactions. The Heck reaction is a way to substitute alkenes.

<span class="mw-page-title-main">Platonic hydrocarbon</span> Organic molecule whose carbon structure is a Platonic solid

In organic chemistry, a Platonic hydrocarbon is a hydrocarbon whose structure matches one of the five Platonic solids, with carbon atoms replacing its vertices, carbon–carbon bonds replacing its edges, and hydrogen atoms as needed.

An alkyne trimerisation is a [2+2+2] cycloaddition reaction in which three alkyne units react to form a benzene ring. The reaction requires a metal catalyst. The process is of historic interest as well as being applicable to organic synthesis. Being a cycloaddition reaction, it has high atom economy. Many variations have been developed, including cyclisation of mixtures of alkynes and alkenes as well as alkynes and nitriles.

<span class="mw-page-title-main">Trimethylsilyl group</span> Functional group

A trimethylsilyl group (abbreviated TMS) is a functional group in organic chemistry. This group consists of three methyl groups bonded to a silicon atom [−Si(CH3)3], which is in turn bonded to the rest of a molecule. This structural group is characterized by chemical inertness and a large molecular volume, which makes it useful in a number of applications.

<span class="mw-page-title-main">Bamford–Stevens reaction</span> Synthesis of alkenes by base-catalysed decomposition of tosylhydrazones

The Bamford–Stevens reaction is a chemical reaction whereby treatment of tosylhydrazones with strong base gives alkenes. It is named for the British chemist William Randall Bamford and the Scottish chemist Thomas Stevens Stevens (1900–2000). The usage of aprotic solvents gives predominantly Z-alkenes, while protic solvent gives a mixture of E- and Z-alkenes. As an alkene-generating transformation, the Bamford–Stevens reaction has broad utility in synthetic methodology and complex molecule synthesis.

Di-<i>tert</i>-butyl dicarbonate Chemical compound

Di-tert-butyl dicarbonate is a reagent widely used in organic synthesis. Since this compound can be regarded formally as the acid anhydride derived from a tert-butoxycarbonyl (Boc) group, it is commonly referred to as Boc anhydride. This pyrocarbonate reacts with amines to give N-tert-butoxycarbonyl or so-called Boc derivatives. These carbamate derivatives do not behave as amines, which allows certain subsequent transformations to occur that would be incompatible with the amine functional group. The Boc group can later be removed from the amine using moderately strong acids. Thus, Boc serves as a protective group, for instance in solid phase peptide synthesis. Boc-protected amines are unreactive to most bases and nucleophiles, allowing for the use of the fluorenylmethyloxycarbonyl group (Fmoc) as an orthogonal protecting group.

<span class="mw-page-title-main">Organosilicon chemistry</span> Organometallic compound containing carbon–silicon bonds

Organosilicon chemistry is the study of organometallic compounds containing carbon–silicon bonds, to which they are called organosilicon compounds. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, flammable, hydrophobic, and stable to air. Silicon carbide is an inorganic compound.

<span class="mw-page-title-main">Directed ortho metalation</span> Chemical reaction

Directed ortho metalation (DoM) is an adaptation of electrophilic aromatic substitution in which electrophiles attach themselves exclusively to the ortho- position of a direct metalation group or DMG through the intermediary of an aryllithium compound. The DMG interacts with lithium through a hetero atom. Examples of DMG's are the methoxy group, a tertiary amine group and an amide group.The compound can be produced by directed lithiation of anisole.

<i>tert</i>-Butyloxycarbonyl protecting group Protecting group used in organic synthesis

The tert-butyloxycarbonyl protecting group or tert-butoxycarbonyl protecting group is an acid-labile protecting group used in organic synthesis.

The Fleming–Tamao oxidation, or Tamao–Kumada–Fleming oxidation, converts a carbon–silicon bond to a carbon–oxygen bond with a peroxy acid or hydrogen peroxide. Fleming–Tamao oxidation refers to two slightly different conditions developed concurrently in the early 1980s by the Kohei Tamao and Ian Fleming research groups.

<span class="mw-page-title-main">Disilyne</span> Chemical compound

Disilyne is a silicon hydride with the formula Si
2H
2. Several isomers are possible, but none are sufficiently stable to be of practical value. Substituted disilynes contain a formal silicon–silicon triple bond and as such are sometimes written R2Si2 (where R is a substituent group). They are the silicon analogues of alkynes.

<span class="mw-page-title-main">Dyotropic reaction</span>

A dyotropic reaction in organic chemistry is a type of organic reaction and more specifically a pericyclic valence isomerization in which two sigma bonds simultaneously migrate intramolecularly. The reaction type is of some relevance to organic chemistry because it can explain how certain reactions occur and because it is a synthetic tool in the synthesis of organic molecules for example in total synthesis. It was first described by Manfred T. Reetz in 1971 In a type I reaction two migrating groups interchange their relative positions and a type II reaction involves migration to new bonding sites without positional interchange.

Tetra-tert-butylmethane is a hypothetical organic compound with formula C17H36, consisting of four tert-butyl groups bonded to a central carbon atom. It would be an alkane, specifically the most compact branched isomer of heptadecane.

<span class="mw-page-title-main">Trisilaallene</span> Class of silicon chemical compounds

Trisilaallene is a subclass of silene derivatives where a central silicon atom forms double bonds with each of two terminal silicon atoms, with the generic formula R2Si=Si=SiR2. Trisilaallene is a silicon-based analog of an allene, but their chemical properties are markedly different.

<span class="mw-page-title-main">Phosphasilene</span>

Phosphasilenes or silylidenephosphanes are a class of compounds with silicon-phosphorus double bonds. Since the electronegativity of phosphorus (2.1) is higher than that of silicon (1.9), the "Si=P" moiety of phosphasilene is polarized. The degree of polarization can be tuned by altering the coordination numbers of the Si and P centers, or by modifying the electronic properties of the substituents. The phosphasilene Si=P double bond is highly reactive, yet with the choice of proper substituents, it can be stabilized via donor-acceptor interaction or by steric congestion.

Pnictogen-substituted tetrahedranes are pnictogen-containing analogues of tetrahedranes with the formula RxCxPn4-x. Computational work has indicated that the incorporation of pnictogens to the tetrahedral core alleviates the ring strain of tetrahedrane. Although theoretical work on pnictogen-substituted tetrahedranes has existed for decades, only the phosphorus-containing species have been synthesized. These species exhibit novel reactivities, most often through ring-opening and polymerization pathways. Phosphatetrahedranes are of interest as new retrons for organophosphorus chemistry. Their strain also make them of interest in the development of energy-dense compounds.

References

  1. ↑ Maier, G.; Pfriem, S.; Schäfer, U.; Matusch, R. (1978). "Tetra-tert-butyltetrahedrane". Angew. Chem. Int. Ed. Engl. 17 (7): 520–521. doi:10.1002/anie.197805201.
  2. ↑ Nemirowski, Adelina; Reisenauer, Hans Peter; Schreiner, Peter R. (2006). "Tetrahedrane—Dossier of an Unknown". Chem. Eur. J. 12 (28): 7411–7420. doi:10.1002/chem.200600451. PMID   16933255.
  3. ↑ Ren, Xiao-Yuan; Jiang, Cai-Ying; Wang, Jiang; Liu, Zi-Yang (2008). "Endohedral complex of fullerene C60 with tetrahedrane, C4H4@C60". J. Mol. Graph. Model. 27 (4): 558–562. doi:10.1016/j.jmgm.2008.09.010. PMID   18993098.
  4. ↑ Zhou, Ge; Zhang, Jing-Lai; Wong, Ning-Bew; Tian, Anmin (2004). "Computational studies on a kind of novel energetic materials tetrahedrane and nitro derivatives". Journal of Molecular Structure: Theochem. 668 (2–3): 189–195. doi:10.1016/j.theochem.2003.10.054.
  5. ↑ Jarowski, Peter D.; Diederich, Francois; Houk, Kendall N. (2005). "Structures and Stabilities of Diacetylene-Expanded Polyhedranes by Quantum Mechanics and Molecular Mechanics". Journal of Organic Chemistry . 70 (5): 1671–1678. doi:10.1021/jo0479819. PMID   15730286.
  6. ↑ Maier, Günther; Boßlet, Friedrich (1972). "tert-Butyl-substituierte cyclobutadiene und cyclopentadienone" [tert-Butyl-substituted cyclobutadienes and cyclopentadienones]. Tetrahedron Letters. 13 (11): 1025–1030. doi:10.1016/S0040-4039(01)84500-7.
  7. ↑ Maier, Günther; Pfriem, Stephan; Schäfer, Ulrich; Malsch, Klaus-Dieter; Matusch, Rudolf (December 1981). "Kleine Ringe, 38: Tetra-tert-butyltetrahedran". Chemische Berichte (in German). 114 (12): 3965–3987. doi:10.1002/cber.19811141218.
  8. ↑ Lewars, Errol. (2008). Modeling marvels : computational anticipation of novel molecules. [Dordrecht]: Springer. ISBN   978-1-4020-6973-4. OCLC   314371890.
  9. ↑ Eliel, Ernest L. (Ernest Ludwig), 1921-2008. (1994). Stereochemistry of organic compounds. Wilen, Samuel H., Mander, Lewis N. New York: Wiley. ISBN   0-471-01670-5. OCLC   27642721.{{cite book}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  10. ↑ Maier, Günther; Fleischer, Frank (1991-01-01). "Ein alternativer zugang zum tetra-tert-butyltetrahedran". Tetrahedron Letters (in German). 32 (1): 57–60. doi:10.1016/S0040-4039(00)71217-2. ISSN   0040-4039.
  11. ↑ Rubin, M.; Rubina, M.; Gevorgyan, V. (2006). "Recent Advances in Cyclopropene Chemistry". Synthesis. 2006 (8): 1221–1245. doi:10.1055/s-2006-926404.
  12. ↑ Nakamoto, M.; Inagaki, Y.; Ochiai, T.; Tanaka, M.; Sekiguchi, A. (2011). "Cyclobutadiene to tetrahedrane: Valence isomerization induced by one-electron oxidation". Heteroatom Chemistry. 22 (3–4): 412–416. doi:10.1002/hc.20699.
  13. ↑ Maier, Günther; Neudert, Jörg; Wolf, Oliver; Pappusch, Dirk; Sekiguchi, Akira; Tanaka, Masanobu; Matsuo, Tsukasa (2002). "Tetrakis(trimethylsilyl)tetrahedrane". J. Am. Chem. Soc. 124 (46): 13819–13826. doi:10.1021/ja020863n. PMID   12431112.
  14. ↑ Sekiguchi, Akira; Tanaka, Masanobu (2003). "Tetrahedranyllithium: Synthesis, Characterization, and Reactivity". J. Am. Chem. Soc. 125 (42): 12684–5. doi:10.1021/ja030476t. PMID   14558797.
  15. ↑ Nakamoto, Masaaki; Inagaki, Yusuke; Nishina, Motoaki; Sekiguchi, Akira (2009). "Perfluoroaryltetrahedranes: Tetrahedranes with Extended σ−π Conjugation". J. Am. Chem. Soc. 131 (9): 3172–3. doi:10.1021/ja810055w. PMID   19226138.
  16. ↑ Ochiai, Tatsumi; Nakamoto, Masaaki; Inagaki, Yusuke; Sekiguchi, Akira (2011). "Sulfur-Substituted Tetrahedranes". J. Am. Chem. Soc. 133 (30): 11504–7. doi:10.1021/ja205361a. PMID   21728313.
  17. ↑ Kobayashi, Y.; Nakamoto, M.; Inagaki, Y.; Sekiguchi, A. (2013). "Cross-Coupling Reaction of a Highly Strained Molecule: Synthesis of σ–π Conjugated Tetrahedranes". Angew. Chem. Int. Ed. 52 (41): 10740–10744. doi:10.1002/anie.201304770. PMID   24038655. S2CID   30151404.
  18. ↑ Tanaka, M.; Sekiguchi, A. (2005). "Hexakis(trimethylsilyl)tetrahedranyltetrahedrane". Angew. Chem. Int. Ed. 44 (36): 5821–5823. doi:10.1002/anie.200501605. PMID   16041816.
  19. ↑ Ichinohe, Masaaki; Toyoshima, Masafumi; Kinjo, Rei; Sekiguchi, Akira (2003). "Tetrasilatetrahedranide: A Silicon Cage Anion". J. Am. Chem. Soc. 125 (44): 13328–13329. doi:10.1021/ja0305050. PMID   14583007.
  20. ↑ Fischer, G.; Huch, V.; Mayer, P.; Vasisht, S. K.; Veith, M.; Wiberg, N. (2005). "Si8(SitBu3)6: A Hitherto Unknown Cluster Structure in Silicon Chemistry". Angewandte Chemie International Edition . 44 (48): 7884–7887. doi:10.1002/anie.200501289. PMID   16287188.
  21. ↑ Uhl, Werner; Graupner, Rene; Layh, Marcus; Schütz, Uwe (1995). "In4{C(SiMe3)3}4 mit In4-tetraeder und In4Se4{C(SiMe3)3}4 mit In4Se4-heterocubanstruktur". Journal of Organometallic Chemistry. 493 (1–2): C1–C5. doi:10.1016/0022-328X(95)05399-A.
  22. ↑
    • Organometallics 2019, 38, 21, 4054–4059.
    • Organometallics 1984, 3, 1574−1583.
    • Organometallics 1986, 5, 25−33.
    • J. Am. Chem. Soc. 1984, 106, 3356−3357.
    • J. Chem. Soc., Chem. Commun. 1984, 485−486.
    • Science Advances 25 Mar 2020: Vol. 6, no. 13, doi:10.1126/sciadv.aaz3168
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.