Arsabenzene

Arsabenzene
Names
	Preferred IUPAC name Arsinine
	Systematic IUPAC name Arsinine
	Other names Arsabenzene
Identifiers
CAS Number	289-31-6 ;
3D model (JSmol)	Interactive image ;
ChemSpider	119909 ;
PubChem CID	136132 ;
CompTox Dashboard (EPA)	DTXSID90183093 ;
	InChI InChI=1S/C5H5As/c1-2-4-6-5-3-1/h1-5H Key: XRFXFAVKXJREHL-UHFFFAOYSA-N ; InChI=1/C5H5As/c1-2-4-6-5-3-1/h1-5H Key: XRFXFAVKXJREHL-UHFFFAOYAM;
	SMILES C1=CC=[As]C=C1;
Properties
Chemical formula	C5H5As
Molar mass	140.017 g·mol−1
Appearance	Colourless gas
Odor	Onion like
Melting point	−54 °C (−65 °F; 219 K)
Boiling point	−54 to 25 °C (−65 to 77 °F; 219 to 298 K)
Structure
Molecular shape	planar
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Last updated July 18, 2023

Arsabenzene (IUPAC name: arsinine) is an organoarsenic heterocyclic compound with the chemical formula C₅H₅As. It belongs to a group of compounds called heteroarenes that have the general formula C₅H₅E (E= N, P, As, Sb, Bi).^[1]

Structure

Arsabenzene is planar. The C—C bond distances of 1.39 Å, the As—C bond has a length of 1.85 Å, this is 6.6% shorter than the normal As—C single bond.^[1]

NMR spectroscopy carried out on arsabenzene indicates that it has a diamagnetic ring current.^[6]

Synthesis

Arsabenzene is synthesized in a two step process from 1,4-pentadiyne. The diyne reacts with dibutylstannane to give 1,1-dibutylstannacyclohexa-2,5-diene.^[1] The organotin compound undergoes As/Sn exchange with arsenic trichloride to give 1-chloroacyclohexadiene, which loses a HCl upon heating, forming the arsabenzene.^[1]

CH₂(CHCH)₂SnBu₂ + AsCl₃ → CH₂(CHCH)₂AsCl + Bu₂SnCl₂

CH₂(CHCH)₂AsCl → C₅H₅As + HCl

Reactions

Arsabenzene undergoes electrophilic aromatic substitution at its ortho and para positions. It also undergoes Friedel-Crafts acylation.^[2]

Whereas pyridine does not normally undergo a Diels–Alder reaction, arsabenzene behaves as a diene with hexafluoro-2-butyne. The corresponding phosphorine and benzene undergo the analogous reaction at 100 °C and 200 °C, respectively. Thus the ability of these heterobenzenes to undergo the Diels Alder reaction with this electrophile increases down the periodic table. Bismabenzene is so reactive that it exists in equilibrium with its dimer.^[5]

Arsabenzene is far less basic than pyridine, being unreactive with Lewis acids. Trifluoroacetic acid does not protonate the molecule.^[5]

Related Research Articles

Aromatic compounds, also known as "mono- and polycyclic aromatic hydrocarbons", are organic compounds containing one or more aromatic rings. The word "aromatic" originates from the past grouping of molecules based on smell, before their general chemical properties were understood. The current definition of aromatic compounds does not have any relation with their smell.

Pyridine is a basic heterocyclic organic compound with the chemical formula C₅H₅N. It is structurally related to benzene, with one methine group (=CH−) replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a distinctive, unpleasant fish-like smell. Pyridine is colorless, but older or impure samples can appear yellow, due to the formation of extended, unsaturated polymeric chains, which show significant electrical conductivity. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Historically, pyridine was produced from coal tar. As of 2016, it is synthesized on the scale of about 20,000 tons per year worldwide.

Cyclopentadiene is an organic compound with the formula C₅H₆. It is often abbreviated CpH because the cyclopentadienyl anion is abbreviated Cp⁻.

The following outline is provided as an overview of and topical guide to organic chemistry:

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

Phosphorine is a heavier element analog of pyridine, containing a phosphorus atom instead of an aza- moiety. It is also called phosphabenzene and belongs to the phosphaalkene class. It is a colorless liquid that is mainly of interest in research.

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

A silabenzene is a heteroaromatic compound containing one or more silicon atoms instead of carbon atoms in benzene. A single substitution gives silabenzene proper; additional substitutions give a disilabenzene, trisilabenzene, etc.

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

Borabenzene is a hypothetical organoboron compound with the formula C₅H₅B. Unlike the related but highly stable benzene molecule, borabenzene would be electron-deficient. Related derivatives are the boratabenzene anions, including the parent [C₅H₅BH]⁻.

Oxazole is the parent compound for a vast class of heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitrogen separated by one carbon. Oxazoles are aromatic compounds but less so than the thiazoles. Oxazole is a weak base; its conjugate acid has a pK_a of 0.8, compared to 7 for imidazole.

Triazines are a class of nitrogen-containing heterocycles. The parent molecules' molecular formula is C₃H₃N₃. They exist in three isomeric forms, 1,3,5-triazines being common.

A nucleophilic aromatic substitution is a substitution reaction in organic chemistry in which the nucleophile displaces a good leaving group, such as a halide, on an aromatic ring. Aromatic rings are usually nucleophilic, but some aromatic compounds do undergo nucleophilic substitution. Just as normally nucleophilic alkenes can be made to undergo conjugate substitution if they carry electron-withdrawing substituents, so normally nucleophilic aromatic rings also become electrophilic if they have the right substituents.

<span class="mw-page-title-main">Cyclic compound</span> Molecule with a ring of bonded atoms

A cyclic compound is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where all the atoms are carbon, none of the atoms are carbon, or where both carbon and non-carbon atoms are present. Depending on the ring size, the bond order of the individual links between ring atoms, and their arrangements within the rings, carbocyclic and heterocyclic compounds may be aromatic or non-aromatic; in the latter case, they may vary from being fully saturated to having varying numbers of multiple bonds between the ring atoms. Because of the tremendous diversity allowed, in combination, by the valences of common atoms and their ability to form rings, the number of possible cyclic structures, even of small size numbers in the many billions.

Pyrylium is a cation with formula C₅H₅O⁺, consisting of a six-membered ring of five carbon atoms, each with one hydrogen atom, and one positively charged oxygen atom. The bonds in the ring are conjugated as in benzene, giving it an aromatic character. In particular, because of the positive charge, the oxygen atom is trivalent. Pyrilium is a mono-cyclic and heterocyclic compound, one of the oxonium ions.

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

Stannabenzene (C₅H₆Sn) is the parent representative of a group of organotin compounds that are related to benzene with a carbon atom replaced by a tin atom. Stannabenzene itself has been studied by computational chemistry, but has not been isolated.

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

Organolead chemistry is the scientific study of the synthesis and properties of organolead compounds, which are organometallic compounds containing a chemical bond between carbon and lead. The first organolead compound was hexaethyldilead (Pb₂(C₂H₅)₆), first synthesized in 1858. Sharing the same group with carbon, lead is tetravalent.

Thiopyrylium is a cation with the chemical formula C₅H₅S⁺. It is analogous to the pyrylium cation with the oxygen atom replaced by a sulfur atom.

In Lewis acid catalysis of organic reactions, a metal-based Lewis acid acts as an electron pair acceptor to increase the reactivity of a substrate. Common Lewis acid catalysts are based on main group metals such as aluminum, boron, silicon, and tin, as well as many early and late d-block metals. The metal atom forms an adduct with a lone-pair bearing electronegative atom in the substrate, such as oxygen, nitrogen, sulfur, and halogens. The complexation has partial charge-transfer character and makes the lone-pair donor effectively more electronegative, activating the substrate toward nucleophilic attack, heterolytic bond cleavage, or cycloaddition with 1,3-dienes and 1,3-dipoles.

Pentamethylcyclopentadienyl rhodium dichloride dimer is an organometallic compound with the formula [(C₅(CH₃)₅RhCl₂)]₂, commonly abbreviated [Cp*RhCl₂]₂ This dark red air-stable diamagnetic solid is a reagent in organometallic chemistry.

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

Selenopyrylium is an aromatic heterocyclic compound consisting of a six-membered ring with five carbon atoms and a positively charged selenium atom.

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

Telluropyrylium is an aromatic heterocyclic compound consisting of a six member ring with five carbon atoms, and a positively charged tellurium atom. Derivatives of telluropyrylium are important in research of infrared dyes.

Stibinin, also known as stibabenzene, is an organic chemical compound. Stibinin has the chemical formula C₅H₅Sb. The molecule, stibinin, is a derivative of benzene, with one of the carbon atoms in the 6-membered ring replaced by an antimony (Sb) atom. Stibinin is a molecule that is considered to be an organoantimony compound due to it containing carbon, hydrogen, and antimony atoms.

References

1 2 3 4 5 Elschenbroich, C. (2006). Organometallics (in German). Wiley-VCH Weinheim. pp. 229–230. ISBN 3-527-29390-6.
1 2 Cadogan, J. I. G.; Buckingham, J.; Macdonald, F. (1997). Dictionary of Organic Compounds. Vol. 10 (6th ed.). CRC Press. p. 491. ISBN 0-412-54110-6.
↑ Sadimenko, A. P. (2005). Organometallic Complexes of B-, Si- (Ge-), and P- (As-, Sb-) Analogues of Pyridine. Advances in Heterocyclic Chemistry. Vol. 89. pp. 125–157. doi:10.1016/S0065-2725(05)89003-8. ISBN 9780120207893.
1 2 Eicher, T.; Hauptmann, S.; Suschitzky, H.; Suschitzky, J. (2003). The Chemistry of Heterocycles: Structure, Reactions, Syntheses, and Applications (in German) (2nd ed.). Wiley-VCH Weinheim. p. 368. ISBN 3-527-30720-6.
1 2 3 Ashe, A. J. (1978). "The Group 5 Heterobenzenes". Accounts of Chemical Research. 11 (4): 153–157. doi:10.1021/ar50124a005.
↑ Ashe, A. J.; Chan, W.; Smith, T. W.; Taba, K. M. (1981). "Electrophilic Aromatic Substitution Reactions of Arsabenzene". Journal of Organic Chemistry. 46 (5): 881–885. doi:10.1021/jo00318a012.

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[Ebroich-1] 1 2 3 4 5 Elschenbroich, C. (2006). Organometallics (in German). Wiley-VCH Weinheim. pp. 229–230. ISBN 3-527-29390-6.

[Cardo-2] 1 2 Cadogan, J. I. G.; Buckingham, J.; Macdonald, F. (1997). Dictionary of Organic Compounds. Vol. 10 (6th ed.). CRC Press. p. 491. ISBN 0-412-54110-6.

[3] Sadimenko, A. P. (2005). Organometallic Complexes of B-, Si- (Ge-), and P- (As-, Sb-) Analogues of Pyridine. Advances in Heterocyclic Chemistry. Vol. 89. pp. 125–157. doi:10.1016/S0065-2725(05)89003-8. ISBN 9780120207893.

[Eicher-4] 1 2 Eicher, T.; Hauptmann, S.; Suschitzky, H.; Suschitzky, J. (2003). The Chemistry of Heterocycles: Structure, Reactions, Syntheses, and Applications (in German) (2nd ed.). Wiley-VCH Weinheim. p. 368. ISBN 3-527-30720-6.

[Ashe-5] 1 2 3 Ashe, A. J. (1978). "The Group 5 Heterobenzenes". Accounts of Chemical Research. 11 (4): 153–157. doi:10.1021/ar50124a005.

[6] Ashe, A. J.; Chan, W.; Smith, T. W.; Taba, K. M. (1981). "Electrophilic Aromatic Substitution Reactions of Arsabenzene". Journal of Organic Chemistry. 46 (5): 881–885. doi:10.1021/jo00318a012.

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