![]() | |
![]() | |
![]() | |
Names | |
---|---|
Preferred IUPAC name
2,2′-Bi(1,3-dithiolylidene) | |
Other names
Δ2,2-Bi-1,3-dithiole
| |
Identifiers | |
3D model (
JSmol)
|
|
1282106 | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.045.979 |
EC Number |
|
PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
C6H4S4 | |
Molar mass | 204.34 g·mol−1 |
Appearance | Yellow solid |
Melting point | 116 to 119 °C (241 to 246 °F; 389 to 392 K) |
Boiling point | Decomposes |
Insoluble | |
Solubility in organic solvents | Soluble[ vague] |
Structure | |
0 D | |
Hazards [1] | |
Occupational safety and health (OHS/OSH): | |
Main hazards
|
combustible |
GHS labelling: | |
![]() | |
Warning | |
H317 | |
P261, P280, P302+P352, P333+P313, P363, P501 | |
Related compounds | |
Related compounds
|
|
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Tetrathiafulvalene (TTF) is an organosulfur compound with the formula (C3H2S2)2. Studies on this heterocyclic compound contributed to the development of molecular electronics. TTF is related to the hydrocarbon fulvalene, (C5H4)2, by replacement of four CH groups with sulfur atoms. Over 10,000 scientific publications discuss TTF and its derivatives. [2]
The high level of interest in TTFs has spawned the development of many syntheses of TTF and its analogues. [2] Most preparations entail the coupling of cyclic C3S2 building blocks such as 1,3-dithiole-2-thion or the related 1,3-dithiole-2-ones. For TTF itself, the synthesis begins with the cyclic trithiocarbonate H2C2S2C=S ( 1,3-dithiole-2-thione), which is S-methylated and then reduced to give H2C2S2CH(SCH3) (1,3-dithiole-2-yl methyl thioether), which is treated as follows: [3]
Bulk TTF itself has unremarkable electrical properties. Distinctive properties are, however, associated with salts of its oxidized derivatives, such as salts derived from TTF+.
The high electrical conductivity of TTF salts can be attributed to the following features of TTF:
Each dithiolylidene ring in TTF has 7π electrons: 2 for each sulfur atom, 1 for each sp2 carbon atom. Thus, oxidation converts each ring to an aromatic 6π-electron configuration, consequently leaving the central double bond essentially a single bond, as all π-electrons occupy ring orbitals.
The salt [TTF+
]Cl−
was reported to be a semiconductor in 1972.
[5] Subsequently, the charge-transfer salt [TTF]
TCNQ was shown to be a narrow
band gap semiconductor.
[6]
X-ray diffraction studies of [TTF][TCNQ] revealed stacks of partially oxidized TTF molecules adjacent to anionic stacks of TCNQ molecules. This "segregated stack" motif was unexpected and is responsible for the distinctive electrical properties, i.e. high and
anisotropic
electrical conductivity. Since these early discoveries, numerous analogues of TTF have been prepared. Well studied analogues include tetramethyltetrathiafulvalene (Me4TTF), tetramethylselenafulvalenes (TMTSFs), and bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF, CAS [66946-48-3]).
[7] Several tetramethyltetrathiafulvalene salts (called Fabre salts) are of some relevance as
organic superconductors.
{{
cite book}}
: |journal=
ignored (
help)
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link); Collected Volumes, vol. 9, p. 72.
![]() | |
![]() | |
![]() | |
Names | |
---|---|
Preferred IUPAC name
2,2′-Bi(1,3-dithiolylidene) | |
Other names
Δ2,2-Bi-1,3-dithiole
| |
Identifiers | |
3D model (
JSmol)
|
|
1282106 | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.045.979 |
EC Number |
|
PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
C6H4S4 | |
Molar mass | 204.34 g·mol−1 |
Appearance | Yellow solid |
Melting point | 116 to 119 °C (241 to 246 °F; 389 to 392 K) |
Boiling point | Decomposes |
Insoluble | |
Solubility in organic solvents | Soluble[ vague] |
Structure | |
0 D | |
Hazards [1] | |
Occupational safety and health (OHS/OSH): | |
Main hazards
|
combustible |
GHS labelling: | |
![]() | |
Warning | |
H317 | |
P261, P280, P302+P352, P333+P313, P363, P501 | |
Related compounds | |
Related compounds
|
|
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Tetrathiafulvalene (TTF) is an organosulfur compound with the formula (C3H2S2)2. Studies on this heterocyclic compound contributed to the development of molecular electronics. TTF is related to the hydrocarbon fulvalene, (C5H4)2, by replacement of four CH groups with sulfur atoms. Over 10,000 scientific publications discuss TTF and its derivatives. [2]
The high level of interest in TTFs has spawned the development of many syntheses of TTF and its analogues. [2] Most preparations entail the coupling of cyclic C3S2 building blocks such as 1,3-dithiole-2-thion or the related 1,3-dithiole-2-ones. For TTF itself, the synthesis begins with the cyclic trithiocarbonate H2C2S2C=S ( 1,3-dithiole-2-thione), which is S-methylated and then reduced to give H2C2S2CH(SCH3) (1,3-dithiole-2-yl methyl thioether), which is treated as follows: [3]
Bulk TTF itself has unremarkable electrical properties. Distinctive properties are, however, associated with salts of its oxidized derivatives, such as salts derived from TTF+.
The high electrical conductivity of TTF salts can be attributed to the following features of TTF:
Each dithiolylidene ring in TTF has 7π electrons: 2 for each sulfur atom, 1 for each sp2 carbon atom. Thus, oxidation converts each ring to an aromatic 6π-electron configuration, consequently leaving the central double bond essentially a single bond, as all π-electrons occupy ring orbitals.
The salt [TTF+
]Cl−
was reported to be a semiconductor in 1972.
[5] Subsequently, the charge-transfer salt [TTF]
TCNQ was shown to be a narrow
band gap semiconductor.
[6]
X-ray diffraction studies of [TTF][TCNQ] revealed stacks of partially oxidized TTF molecules adjacent to anionic stacks of TCNQ molecules. This "segregated stack" motif was unexpected and is responsible for the distinctive electrical properties, i.e. high and
anisotropic
electrical conductivity. Since these early discoveries, numerous analogues of TTF have been prepared. Well studied analogues include tetramethyltetrathiafulvalene (Me4TTF), tetramethylselenafulvalenes (TMTSFs), and bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF, CAS [66946-48-3]).
[7] Several tetramethyltetrathiafulvalene salts (called Fabre salts) are of some relevance as
organic superconductors.
{{
cite book}}
: |journal=
ignored (
help)
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link); Collected Volumes, vol. 9, p. 72.