Pagodane
Encyclopedia
Pagodane is an organic compound
with formula whose carbon
skeleton was said to resemble a pagoda
, hence the name. It is a polycyclic
hydrocarbon
whose molecule has the D2h point symmetry group. The compound is a highly crystalline solid that melts at 243 °C, is barely soluble in most organic solvents and moderately soluble in benzene
and chloroform
. It sublimes at low pressure.
The name pagodane is used more generally for any member of a family of compounds whose molecular skeletons have the same 16-carbon central cage as the basic compound. Each member can be seen as the result of connecting eight atoms of this cage in pairs by four alkane
chains. The general member is denoted [m.n.p.q]pagodane where m, n, p and q are the number of carbons of those four chains. The general formula is then where s= m+n+p+q. In particular, the basic compound has those carbons connected by four methylene
functional group
s (m=n=p=q=1), and its name within that family is therefore [1.1.1.1]pagodane.
Prinzbach and co-workers remarked that "the obvious need for [the short name 'pagodane'] can be readily understood in view of the von Baeyer/IUPAC and Chemical Abstracts nomenclature", undecacyclo[9.9.0.01,5.02,12.02,18.03,7.06,10.08,12.011,15.013,17.316,20]icosane.
Eight of pagodane's 20 carbon atoms (numbered 3,5,8,10,13,15,18, and 20) have an inverted tetrahedral geometry as in some propellane
s — specifically, [2.2.1]propellane, whose carbon skeleton is a part of pagodane's.
(melting point about 322 °C).
Both [1.1.1.1]pagodane and [2.2.1.1]pagodane form divalent
cations in
/
. In these cations the electron deficiency is spread over the central cyclobutane
ring.
Pagodane is an isomer of dodecahedrane
and can be chemically converted to it.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
with formula whose carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
skeleton was said to resemble a pagoda
Pagoda
A pagoda is the general term in the English language for a tiered tower with multiple eaves common in Nepal, India, China, Japan, Korea, Vietnam and other parts of Asia. Some pagodas are used as Taoist houses of worship. Most pagodas were built to have a religious function, most commonly Buddhist,...
, hence the name. It is a polycyclic
Polycyclic compound
In organic chemistry, a polycyclic compound is a cyclic compound with more than one hydrocarbon loop or ring structures . In general, the term includes all polycyclic aromatic compounds, including the polycyclic aromatic hydrocarbons, the heterocyclic aromatic compounds containing sulfur,...
hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
whose molecule has the D2h point symmetry group. The compound is a highly crystalline solid that melts at 243 °C, is barely soluble in most organic solvents and moderately soluble in benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
and chloroform
Chloroform
Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...
. It sublimes at low pressure.
The name pagodane is used more generally for any member of a family of compounds whose molecular skeletons have the same 16-carbon central cage as the basic compound. Each member can be seen as the result of connecting eight atoms of this cage in pairs by four alkane
Alkane
Alkanes are chemical compounds that consist only of hydrogen and carbon atoms and are bonded exclusively by single bonds without any cycles...
chains. The general member is denoted [m.n.p.q]pagodane where m, n, p and q are the number of carbons of those four chains. The general formula is then where s= m+n+p+q. In particular, the basic compound has those carbons connected by four methylene
Methylene
Methylene is a chemical species in which a carbon atom is bonded to two hydrogen atoms. Three different possibilities present themselves:* the -CH2- substituent group: e.g., dichloromethane ....
functional group
Functional group
In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...
s (m=n=p=q=1), and its name within that family is therefore [1.1.1.1]pagodane.
Synthesis and structure
The compound was first synthesized by H. Prinzbach et al. in 1987, by a 14-step sequence starting from isodrin. In the process they also synthesized [2.2.1.1]pagodane and several derivatives.Prinzbach and co-workers remarked that "the obvious need for [the short name 'pagodane'] can be readily understood in view of the von Baeyer/IUPAC and Chemical Abstracts nomenclature", undecacyclo[9.9.0.01,5.02,12.02,18.03,7.06,10.08,12.011,15.013,17.316,20]icosane.
Eight of pagodane's 20 carbon atoms (numbered 3,5,8,10,13,15,18, and 20) have an inverted tetrahedral geometry as in some propellane
Propellane
In organic chemistry, propellane is any member of a class of polycyclic hydrocarbons, whose carbon skeleton consists of three rings of carbon atoms sharing a common carbon-carbon covalent bond...
s — specifically, [2.2.1]propellane, whose carbon skeleton is a part of pagodane's.
Derivatives
Several derivatives are available, such as the diketoneKetone
In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...
(melting point about 322 °C).
Both [1.1.1.1]pagodane and [2.2.1.1]pagodane form divalent
Valence (chemistry)
In chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element. "Valence" can be defined as the number of valence bonds...
cations in
Antimony pentafluoride
Antimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, the strongest known acid...
/
Sulfuryl chloride fluoride
Sulfuryl chloride fluoride is the chemical compound with the formula SO2ClF. It is employed as a solvent for highly oxidizing compounds.The laboratory-scale synthesis begins with the preparation of potassium fluorosulfite:This salt is then chlorinated to give sulfuryl chloride fluorideFurther...
. In these cations the electron deficiency is spread over the central cyclobutane
Cyclobutane
Cyclobutane is an organic compound with the formula 4. Cyclobutane is a colourless gas and commercially available as a liquefied gas. Derivatives of cyclobutane are called cyclobutanes...
ring.
Pagodane is an isomer of dodecahedrane
Dodecahedrane
Dodecahedrane is a chemical compound first synthesised by Leo Paquette of Ohio State University in 1982, primarily for the "aesthetically pleasing symmetry of the dodecahedral framework"....
and can be chemically converted to it.