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Copolymerization of Tetrameric Thioformaldehyde with Oligomeric Thioformaldehydes Substituted Analogs or Sulfur.

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[I]
[2]
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[4]
[S]
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Transition Metal Carbyne Complexes, Part 35.-Part 34: E . 0. Fischer,
S . WaLz, W R. Wagner, J. Organomet. Chem. 134, C 3 7 (1977).
Review: E. 0. Fischer, U . Schubert, J. Organomet. Chem. 100, 59 (1975).
G. Herzhrry: Molecular Spectra and Molecular Structure, Vol. 11. Van
Nostrand, New York 1964, p. 215.
M . B. C. Drew, K . C . Moss, N . Rolje, Inorg. Nucl. Chem. Lett. 7,
1219 (1971).
C . G. Kreirer, E . 0 . Fischer, Chem. Ber. 103, 1561 (1970).
E . 0. Fischer, G . Kreis, C . G . Kreiter, J . Muller, G . Hurmer, H . Lorenz,
Angew. Chem. 85, 618 (1973); Angew. Chem. Int. Ed. Engl. 12, 564
( 1 973).
Copolymerization of Tetrameric Thioformaldehyde
with Oligomeric Thioformaldehydes, Substituted Analogs, or Sulfur
By M a x Schmidt and Eckhard Weissflog[*]
In acid solution, hydrogen sulfide and formalin afford trimeric thioformaldehyde (CH& [I ,3,5-trithiane (1 )] as well
as polymethylene sulfides (CH2S),. The latter products are
not thermoplastic; their melting or decomposition temperatures depend upon the conditions of their preparation and
vary between 160 and 22OoCC']. The trithiane ( I ) , the oligomeric thioformaldehyde having the highest melting point (ca.
2 15 "C),can be polymerized only under relatively drastic conditions[21.This also applies to the substituted trithianes we
have prepared so far and to some substituted tetrathi~canes[~!
In contrast, it proves much easier to convert tetrameric
thioformaldehyde (CH2S)4[1,3,5,7-tetrathiocane (211 and the
next higher homolog ( C H Z S ) ~into polymethylene sulfide,
which is highly crystalline up to its relatively sharp melting
point (without decomposition) of ca. 240°C, by treatment
with boron trifluoride-diethyl ether[4].
We have now found that the highly reactive intermediate
(3) (diradical or zwitterion?) presumably formed from boron
trifluoride-diethyl ether and the tetrathiocane (2) according
to
C H2-S-C HZ-S-C Hz-S-CHZ-S-BF,
(3)
is able to attack trithianes including ( I ), substituted tetrathiocanes, and elemental sulfur (as well as elemental selenium,
albeit less effectively) in such a way that copolymers with
interesting properties are formed under mild conditions. For
instance, an equimolar mixture of ( 1 ) and (2) reacts with
BF3.Et20 at ca. 100°C to give a practically quantitative
yield of a polymethylene sulfide mixture which melts without
decomposition between 245 and 265°C. Even at a molar ratio
of ( 1 ) to (2) of 4 : 1 the polymeric product (CH2S), is still
formed in 87% yield (although only at ca. 150°C owing to
the higher melting point of the starting mixture).
The oligomeric thioformaldehydes form silver complexes
which can be utilized for their separationr5].The granular
polymer from the above reaction complexes Ag' ions from
aqueous solution. These ions can be eluted with aqueous
NH3 to regenerate the pure polymer.
-
We have already substituted the carbon atom of ( I ) and
(2) to varying degrees on a previous occasion (R=CH3,
Si(CH3)3, Ge(CH3)3, Sn(CH3)3, or C O O H instead of H)[31.
Like pure ( 1 1, these derivatives also undergo BF3-catalyzed
copolymerization with (2). The original substitution pattern
is rediscovered at the carbon atoms of the C-S-C
chains,
modified according to the ratio of the reactants.
The properties of the new polymers are expectedly influenced
by the substituents. They usually have wide melting ranges
and some of them are thermoplastic. Those containing carboxyl groups are suitable for use as ion exchangers (the ion
selectivity has yet to be investigated).
Oligomeric thioformaldehydes and elemental sulfur form
homogeneous melts whose physical properties deviate considerably from those of pure sulfur. Treatment of a molten
mixture of (2) and s8 with BF3.Et20 results in extensive
incorporation of sulfur into the insoluble polymeric product.
Once again the reactive intermediate (3) will first be formed
and open the sulfur rings in a subsequent step:
Procedures (typical examples)
a) Compounds (1) (1.38 g, 0.01 mol) and (2) (1.84g,
0.01 mol) are mixed together and melted. The clear homogeneous melt solidifies within seconds on addition of a small
drop of BF3.E t 2 0 at ca. 100°C. The brittle polymer is ground
mechanically and extracted for 8 h with benzene, whereupon
0.1 3 g of ( 1 ) dissolves. Yield of (CH2S),: 3.09 g (96 %). The
almost colorless product forms a clear melt between 260 and
265 "C; at slightly higher temperature it decomposes slowly
with evolution of gas.
b) Compound (2) (1.84 g, 0.01 mol) and 1,3,5,7-tetrathiocane-2-carboxylic acid[3b1(2.28 g, 0.01 mol) are suspended in
xylene (10 ml) and heated to boiling. After addition of a drop
of BF3. E t 2 0 the mixture is filtered. The solid residue is washed
several times with hot benzene, then with concentrated NH3
solution, and finally with dilute hydrochloric acid. The dried
colorless finely crystalline product melts between 160 and
2OO0C, decomposition with evolution of gas being observed
at 180°C. Yield of [+CH2S),-CH(C0OH)-S-],:
1.73g
(42 %). One carbon atom in eight in the C-S-C
chain bears
a carboxyl group.
c) Compound (2) (0.92 g, 5 mmol) and s8 (0.64 g, 2.5 mmol)
are melted together (ca. 95°C) to form a pale yellow mobile
liquid. At 110°C a drop of BF3.Et20 is added and the mixture
stirred mechanically. Polymerization is complete within about
15 s. The cooled brittle mixture is ground and extracted with
benzene for 48 h. Mainly cyclooctasulfur crystallizes from the
extract. The almost colorless polymer melts with partial
decomposition at 146-149°C. Yield: 1.22g (78.2 % for
(CH2S2)").Thus about half of the sulfur is incorporated into
the insoluble polymer.
Received: October 3, 1977 [Z 859 IE]
German version: Angew. Chem. YO, 52 (1978)
CAS Registry numbers:
(11, 291-21-4; (2), 2373-00-4; ( 3 ) . 65150-28-9; (CH2S)., 30699-99-1; S8.
10544-50-0; 1,3,5,7-tetrathiocane-2-carboxylic
acid, 58925-90-9;
[-(CH 2sj,-CH(COOH j-S-In,
65 149-93- I ; (CH 2s 2)". 65 149-94-2.
[*] Prof. Dr. M. Schmidt, Dr. E. Weissflog
lnstitut f i r Anorganische Chemie der Universitat
Am Hubland, D-8700 Wiirzburg (Germany)
Angew. Chem. I n [ . Ed. Engl. 17 (1978) N o . 1
[l]
Literature survey: P. Kochendiirfer, Dissertation, Universitit Marburg
1964.
51
[2] J. 1. Takeda, K . Hayashi, S. Okamura, J. Appl. Polym. Sci. 13, 1435
(1969); R. C. Gearhart, J . M . Schultr, Makromol. Chem. 177, 835 (1976).
[3] a) M . Schmidt, E. Weissflog, Z. Anorg. Allg. Chem. 418, 208 (1975);
b) Chem. Ber. 109, 1239 (1976).
[4] M . Schmidt, K . Blaettner, P . Kochendorfer, H . Ruf, Z . Naturforsch. B 21,
622 (1966); M . Russo et al., J. Polym. Sci. 8 3 , 455, 501 (1965); E.
Weissflog, Dissertation, Universitat Wiirzburg 1974.
[S] M . Schmidt, E. Weisflog, Z. Anorg. Allg. Chem. 406, 271 (1974).
[Auz(WS4)2I2-,A Novel Inorganic Ring System
By Achim Miiller, Horst Dornfeld, Gerald Henkel, Bernt Krebs,
and M . P . A. Viegersrl
Whereas thioheteroanions, containing a transition element
with an open d shell as central atom can be classified from
the structural point of view according to the rules of
classical complex chemistry['], unexpected and interesting
coordination is found in those thioheteroanions which contain
only metalatomswithclosed d shells,such as [Snz(WS4)z]4-[z1.
We have now isolated a cyclic thioheteroanion as the salt
( 1 ) in the form of dark red crystals
[(C,~H&P]Z[AU~(WS~)~]
by reaction of [ A U ( S ~ O ~ ) with
~ ] ~ -WSi-. Compound ( 1 )
could be characterized by elemental analysis and X-ray
structure analysis, as well as by 1 9 7 A ~
Mossbauer and
vibrational spectroscopy.
The structure of the new gold(1) compound was determined
from single crystal diffractometer data ( R = 6.9 %). (1) crystallizes in the triclinic space group P i with the unit cell constants
u = 12.871(3), b = 11.197(3), c = 11.01l(3)A, a= 119.03(3),
p=91.64(3), y= 108.85(3)". The dimeric, centrosymmetrical
bidentate, nearly
complex anion [ A u ~ ( W S ~- ) ~contains
]~
regular tetrahedral WS: - ligands [average WS bond length :
2.136A (terminal), 2.243A (bridge); SWS bond angles: 105.6112.9(2)"]. The SAuS linkage is approximately linear [SAuS
angle: 167.2(2); AuS bond length: between 2.292(6) and
2.414(6)A].
Though the IR spectrum of ( 1 ) [v(WS) at 494 (m), 489
(m) and v(AuS) at 329 (w) cm-l] shows the coordination
of WS:- as a ligand (with significant differences in comparison
to the spectra of transition metal coordination compounds
where the metal acts as central atom), the molecular structure
cannot be deduced from those data. Useful information has
been obtained from the 77 keV "'Au Mossbauer
the quadrupole splitting and the chemical shift
( Q S = 5.58 mm/s, I S = 0.86 mmjs) constitute proof of an almost
linear SAuS linkagef41,where the bonding involves only 6 s
and 6 p orbitals of gold(r) and the x-acceptor strength of
the ligand WS:- from Au is negligible (in contrast to transition
metal systems with open d shells).
Experimental
To an aqueous solution (600 ml) of Na3[A~(SZ03)2].2H20
(0.1 g) and [(C6H5)4P]Br (0.24g) is quickly added a freshly
prepared solution (20ml HzO) of (NH4)2WS4(0.1g). After
immediate filtration the precipitate is briefly digested in nitromethane (0.7 ml). The residue is dissolved in dimethylformamide (4ml). After addition of ethanol (4 ml) dark red crystals
of ( 1 ) slowly precipitate (about 15 h); yield 0.04 g (27%).
Received: September 29, 1977 [Z 862 IE]
German version: Angew. Chem. 90, 57 (1978)
CAS Registry numbers:
( 1 ), 65015-83-0; Na3[Au(S,0,)2], 12256-50-7; (NHJ2WS4, 13862-78-7
See E. Diemann, A. Miiller, Coord. Chem. Rev. 10, 79 (1973); A. Miiller,
S. Sarkar, Angew. Chem. 89, 748 (1977); Angew. Chem. Int. Ed. Engl.
16, 705 (1977); references cited therein.
[2] A. Miiller, I. Paulat-Boschen, B. Krebs, H . Dornfeld, Angew. Chem. 88,
691 (1976); Angew. Chem. Int. Ed. Engl. 15, 633 (1976); general review
about the structure of compounds with metal-sulfur-metal groups: H .
Vahrenkamp, ibid. 87, 353 (1975) and 14, 322 (1975), respectively.
[3] The spectrum of the powdered sample was measured with a I9'Pt source
(obtained by thermal neutron capture of Ig6Pt)at 4.2 K, normal transmission geometry and integrating counting technique (velocity measurement
with a Michelson interferometer). See M . P . A. Viegers, J . M . Trooster,
Nucl. Instrum. Methods 118,257 (1974). IS relative to I9'Au in Pt.
[4] Seep. G. Jones, A . G . Maddock, M . J . Mays, M . M . Muir, A . F . Williams,
J. Chem. SOC.Dalton Trans. 1977, 1434; M . P. A . Viegers, Thesis, University of Nijmegen 1976.
[I]
Novel Method for the Detection of Indirectly Identifiable Photochemical Intermediates[**]
0 s
O W
Fig. 1. Structure of the cyclic thioheteroanion [Au~ (WS & ]~ -.
The heteroanion is disordered in the crystal structure, the
Au atoms being distributed over three positions. Therefore,
three orientations of identical rings (twisted by nearly 120"
with respect to each other) can be distinguished.
[*I Prof. Dr. A. Miiller ['I, DipLChem. H. Dornfeld
Fakultat fur Chemie der Universitat
Universitatsstrasse, D-4800 Bielefeld (Germany)
Prof. Dr. B. Krebs, Dr. G. Henkel
Anorganisch-chemisches Institut der Universitat
Gievenbecker Weg 9, D-4400 Miinster (Germany)
Dr. M. P. A. Viegers
Research Institute for Materials
University Nijmegen (Netherlands)
['I Author to whom correspondence should be addressed.
52
By Gerd Kaupp and Heinz-Willi Griiterrl
Kinetic, flash spectroscopic, and magnetic (ESR, CIDNP)
methods have been used for the detection of short-lived photointermediates['], but none of these techniques is universally
applicable.
In thermally supported photoreactions a comparison of the
temperature dependence of luminescence and photochemical
quantum yield provides mechanistic data. For example, if
a singlet photoreaction A+P proceeds in two steps via an
intermediate Z, its quantum yield can decrease or increase
A # A*
-z
L
P
[*I
Univ.-Doz. Dr. G. Kaupp, H.-W. Griiter
Chemisches Laboratorium der Universitat
Albertstrasse 21, D-7800 Freiburg (Germany)
[**I This work was supported by the Deutsche Forschungsgemeinschaft
and the Fonds der Chemischen Industrie.
Angew. Chem. Int. Ed. Engl. 17 (1978) No. 1
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