Organic conductors. The synthesis of di-(2,5-dihydrothieno)-1,4,5,8-tetraselenafulvalene (DTTSF) and its charge-transfer salt with 7,7′,8,8′-tetracyano-p-quinodimethane (TCNQ).

Tetrahedron Letters

ORGANIC CONDUCTORS.

No. 24

pp

1719 - 1720,1976.

Pergsmon Prese.

Printed

HI Great

Bntam

THE SYNTEESIS OF DI-(2,5-DIHYDROTBIENO)-1,4,5,8-TETRASELENAFULV~~

tD!iTSF)AND ITS CHAUGE+Ti#iNSFER SALT WITH 7,7',8,t3'-TETRXYANO-p-QUINODIKETAANE

(TCNQ).

C*BergX, K.Eechqaard, J R.Andersen' and C.S.Jacobsen2 (Kermsk Laboratorlum

II,

B C.Drsted Instltutet, DK-2100, Denmark)

(Received XI UK 11 March 1976; accepted Several charge-transfer

for

publlcatlon

5 April

salts of sulphur- and selenium-containing

7,7',8,8'-tetra~ano-p-quinod~methane

1976)

heteroFu1valene.s with

(TCNQ) have recently been shown to possess unique

solid state propertles 3,4,5,6,7 Of the tetraselenafulvalenes

prepared so far,

IMPSF

(I)

has been of partacular

because HMTSF-TCNQ6

1s the first example of an organic compound whxch

trlcal conductxvlty

at very low temperatures

(uO 03Kw600cfi cm)

retains

Interest high elec-

1

sD?HID co=cD (111

(11 D~-(Z,S-d~hydreth~~o)-~3,4-b,3,4-h~-1,4,5,8-tetraselenafulvalene, sized xn order to rnvestxgate the effect of lntroduclng

DTIXF

a polarlsable

(II), was syntbe-

heteroatom

Into the

exocycllc rings, while retalnlng the overall size and symmetry, and thereby probably the packing propertles, 1,2,3-thiadlazoles thlole-2-thrones

of the congener

(HMTSF)

are known to react with a 1,3-dipolarophlle

such as CS2 to qlve 1,3-dl-

ln low to moderate yields'. Recently It was shown that 1,2,3-selenadxazo-

les can react xn an analogous manner to form 1,3-thlaselenole-2-thrones, re converted to dlthladlselenafulvalenes

We report the reaction of 4,6-dlhydro-(3,4-d)-thleno-1,2,3-selenadlazole to yield the 1,3-dlselenole-Z-selone

which U-I turn we-

9

(IV)

(III) wltb CSe2

10

1720

No. 20

(IV) "as treated with trxethylphoephlte (III) was prepared

to give DTTSF

from dlhydrothlophene-3-one

glacial acetrc acrd by a procedure

(II).

sem~carbazone

11

by ring closure w1t.h Se02 rn

analogous to that of Yalpanl -et al

as colourless needles rn 18% yield, m p

85-87o(hexane),

12

. (1111 was Isolated

and rdentrfred as being

(III) ra-

ther than the other possrble rsomer, 4,5-d~hydro-(2,3-d)-threno-1,2,3-selenad~azole,

by

1 H-NMR spectroscopy. Reactlon of (III) wrth excess CSe2 in borlrng toluene X5-166*

MS

(2h) afforded

(IV) in 35% yield, m p

M+ XI accordance wrth the calculated zsotoplc cluster for C5H4SSe3

NMR(CDC131

4.07(s) 6 relatrve to TMS Trrethylphosphlte

coupling of (IV) rn toluene

yield as black crystals, m p

(24h, 1OOo) gave the rnsoiuble

)

228-230°(decomp

isotopic cluster for CloH8S2Se4

m(C6H5CN).

MS

(II) rn 7-10%

M+ U-I accordance with the calculated

Amax Clog E)

31: (3.92), 438 (2.70) and 495

(2 72) nm (IX)

forms a highly conducting 1 1 charge-transfer

needles of typrcal drmenslons v1tres of at least 600 (a cm) the

temperature-dependent

1 x 0 02 x 0 004 mm were obtained -1

From chlorobenzene Room-temperature

were measured by 4-probe technrques

electrIca

propertres ~11

References Kemrafdelzngen,

salt wrth TCNQ

black

CondUCtl-

A detarled account of

appear elsewhere

and NcteS

Rzs$, DK-4000, Denmark

Fyslsk Laboratorlum

III, DTH, DK-2800, Denmark

For a review, see A F Garrto and A J Heeger, Act Chem Res , 1232 E M Engler and V V Patel, J Ames Chem Sot

(1974)

, 96 7376 (1974) , Chem Commun , 937 (1974)

K Bechgaard, D-0 Cowan and A N Blcch, J Chem Sot

A N Bloch, D 0 Cowan, K Bechgaard, R E Pyle, R H Banks and T-0 Poehler, Phys Rev Let-

7.

ters, -34 1561 (1975) (a) M.V Laksm~kantham,

8

R Hursgen and V Webernd&rfer,

9

H K Spencer,

M P Cava ard A F.GarltO, J Chem Sot

(b) E M Engler and V V Patel, K

671 (1975)

Experlentla,

M V Laksmrkantham,

, Chem Commun , 383 (1975)

-17 566

(1961)

M P cava and A F Garlto, J Chem SOC

, Chem CommUn ,

867 (1975) 10

L Henrlksen

11

P Karrer and H Schmrd, Helv Chum Acta, _ 27 116 (1944)

and E S Chrlstransen,

Int J Sulfur Chem

12

I Lalezarl, A Shafree and M Yalpanr, J Org Chem

Part A, 2 13 (1972)

, 36 2836 (1971)