Products of the oxidation of 1-(di-amino-methyl-ene)thio-urea with hydrogen peroxide

Article abstract of DOI:10.1107/S0108270108032769

Two oxidation products of 1-(diamino-methyl-ene)thio-urea (HATU) are reported, obtained from reactions with hydrogen peroxide at two different concentrations; these are 3,5-diamino-1,2,4-thia-diazole, C2H4N4S, (I), related to HATU by intra-molecular N - S bond formation, and 1-(diamino-methyl-ene) uronium hydrogen sulfate, C2H7N4O⁺·HSO4 ^-, (II). In (I), mol-ecular hydrogen-bonded chains could be distinguished, further organized in a herring-bone-like pattern. The structure of (II) is stabilized by an extensive network of N - H...O and O - H...O hydrogen bonds, where hydrogen-bonded anion chains and characteristic cation-anion motifs are present. The compounds are of importance not only with respect to crystal engineering, but also in the design of new synthetic routes to HATU transition metal complexes.

Full text of DOI:10.1107/S0108270108032769

organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
Ray, 1952); and those with Cu, Ag and Zn (Roy & Saha, 1980).
The structures of HATU itself and of some simple salts
derived from HATU have been reported recently (Janczak &
Perp e´ tuo, 2008a,b; Perp e´ tuo & Janczak, 2008).
ISSN 0108-2701
As a thiourea, HATU can be expected to undergo oxidation
reactions yielding different products depending on the reac-
tion conditions. Structure determinations undertaken so far
concern the oxidation products only of substituted thioureas
Products of the oxidation of
1-(diaminomethylene)thiourea with
(e.g. Mamaeva & Bakibaev, 2003). In particular, Butler et al.
(1978) determined the crystal structure of the so-called
hydrogen peroxide
Hector’s base (Hector, 1889) 5-imino-4-phenyl-3-phenyl-
amino-4H-1,2,4-thiadiazoline, which was controversial for 100
years. Hector’s bases are formed on oxidation of monoaryl-
thioureas and on base-catalysed rearrangement yield 3,5-
bis(arylamino)-1,2,4-thiadiazoles, known as Dost’s bases
Małgorzata Hoły n´ ska* and Maria Kubiak
Faculty of Chemistry, University of Wrocław, 14 Joliot-Curie Street, 50-383
Wrocław, Poland
Correspondence e-mail: holynska@wcheto.chem.uni.wroc.pl
(Christophersen et al., 1975; Butler et al., 1980, 1986).
Chilwana & Simoyi (2004) investigated the kinetics of
Received 21 September 2008
Accepted 10 October 2008
Online 22 October 2008
1-(diaminomethylene)thiourea oxidation with bromate(V)
and iodate(VII) ions. In the case of the reaction with
bromate(V) ions, 1-(diaminomethylene)urea was mentioned
as the final product, whereas the reaction with iodate(VII)
ions yields 3,5-diamino-1,2,4-thiadiazole, (I). The latter
oxidation product is interestingly related to HATU as its
cyclization product; however, no crystal structure determina-
tion has been attempted so far.
Two oxidation products of 1-(diaminomethylene)thiourea
(HATU) are reported, obtained from reactions with hydrogen
peroxide at two different concentrations; these are 3,5-
diamino-1,2,4-thiadiazole, C H N S, (I), related to HATU by
intramolecular N—S bond formation, and 1-(diaminomethyl-
2
4
4
+
ꢁ
ene)uronium hydrogen sulfate, C H N O ꢀHSO , (II). In (I),
2
7
4
4
molecular hydrogen-bonded chains could be distinguished,
further organized in a herring-bone-like pattern. The structure
of (II) is stabilized by an extensive network of N—Hꢀ ꢀ ꢀO and
O—Hꢀ ꢀ ꢀO hydrogen bonds, where hydrogen-bonded anion
chains and characteristic cation–anion motifs are present. The
compounds are of importance not only with respect to crystal
engineering, but also in the design of new synthetic routes to
HATU transition metal complexes.
In this paper, the crystal structure of (I), obtained as a
HATU oxidation product with a 3% aqueous solution of
hydrogen peroxide, is reported. When 30% hydrogen
peroxide was used, compound (II) could be isolated. Both (I)
and (II) are of importance not only with respect to crystal
engineering, but also in the design of new synthetic routes
leading to HATU transition metal complexes. Compound (I)
could be considered as the product of intramolecular N—S
bond formation in the 1-(diaminomethylene)thiourea mol-
ecule (Fig. 1 and Table 1). This cyclization apparently does not
lead to charge delocalization. As a result, the N1—C1 and
N1—C2 bond lengths are not equal (Table 1). A literature
survey leads to the conclusion that the most similar compound
with available crystal structure data is 3,5-bis(diphenylamino)-
Comment
1-(Diaminomethylene)thiourea (HATU) is a derivative of
biuret, in which one O atom has been notionally replaced by
an S atom while the remaining amide group has been replaced
by –CH(NH ) . This simple molecule has attracted interest for
2
2
its use as a starting compound to obtain so-called ‘metalla-
cages’, e.g. [Ni (ATU) Cl](ClO ) (where ATU is the depro-
6
8
4 3
tonated form of HATU; Diaz et al., 2004; Gale & Quesada,
006; Gimeno & Vilar, 2006; Lankshear & Beer, 2006). Such
2
compounds are formed only in the presence of chloride ions,
so that the reaction could serve as a method of colorimetric
chloride detection. HATU has also been used as a component
of resins chelating such ions as Ag (Trochimczuk & Kolarz,
2000). The reported transition metal complexes containing
+
HATU as a ligand with known structure include the
complexes with Ni (Kabir et al., 2002; Vilar et al., 1998, 1999;
Diaz et al., 2004), Pd (Chakrabarty et al., 1990; Doxiadi et al.,
2003), Ni and Pd (Cheng et al., 2001; Vilar et al., 1999; Doxiadi
et al., 2003). Metal complexes with HATU of so far unknown
structure include the nitrosyl complexes with Co, Fe and Ru
(Roy & Saha, 1980); the complexes with Co and Hg (Poddar &
Figure 1
The molecular structure of (I). Displacement ellipsoids are drawn at the
30% probability level.
Acta Cryst. (2008). C64, o609–o612
doi:10.1107/S0108270108032769
# 2008 International Union of Crystallography o609

organic compounds
1
,2,4-thiadiazole (Senda & Maruha, 1985), investigated during
in an intramolecular N—Hꢀ ꢀ ꢀO hydrogen bond as an acceptor
(Table 3). Thus, a hydrogen-bonded ring consisting of atoms
N1, C1, C2, O1 and N4, lying in one plane, is formed. Atoms
N2 and N3 from the amine groups bonded to atoms C1 and C2
systematic studies on the oxidation of substituted thioureas by
the iron(III) ion. This compound can be considered as the
derivative of (I) with the H atoms of both amine groups
replaced by phenyl rings. The 1,2,4-thiadiazole ring geometric
parameters are in good agreement in the two compounds. In
˚
deviate from this plane by 0.028 (2) and 0.035 (2) A, respec-
tively. The 1-(diaminomethylene)uronium cation geometrical
parameters are consistent with the data reported for other
salts [e.g. the sulfate hydrate (Lotsch & Schnick, 2005) and
hydrogen chloride (Scoponi et al., 1991)]. It is assumed that
the cation is stabilized by ꢀ-electron delocalization, which is
reflected by the C1—N1 and C2—N1 bond lengths [1.406 (2)
(I), all atoms constituting the 1,2,4-thiadiazole ring lie in one
plane, whereas the two amine substituents (containing atoms
N2 and N3) deviate from the ring plane by 0.036 (2) and
˚
0.054 (2) A (above and below the plane), respectively.
Molecules of (I) form hydrogen-bonded dimers linked
ii
˚
through an N2—H21ꢀ ꢀ ꢀN1 (symmetry code as in Table 2)
and 1.366 (2) A, respectively].
2
hydrogen bond to form R (8) rings (Etter et al., 1990), which
In the hydrogen sulfate anion, the H atom is statistically
disordered over two half-occupied positions; in one position it
is bonded to atom O31 and in the second position to atom
O21. In both positions, this H atom participates in O—Hꢀ ꢀ ꢀO
hydrogen bonds, with a hydrogen sulfate O atom involved as
2
i
are further linked through an N3—H31ꢀ ꢀ ꢀN4 hydrogen bond
2
2
with the formation of a second type of R (8) ring (Fig. 2). The
resulting molecular chains along [001] adopt a herring-bone-
like arrangement in (I). Adjacent chains form very weak
3
contacts between atom H32 at (x, y, z) and atom S1 at (ꢁx + ,
2
1
1
y ꢁ , ꢁz + ).
2
2
Compound (II) is a salt consisting of 1-(diaminomethyl-
ene)uronium cations and hydrogen sulfate anions. The cation,
+
in comparison with the similar [HATUH] cation present, for
example, in 1-(diaminomethylene)thiouron-1-ium chloride
(
Perp e´ tuo & Janczak, 2008), differs by the presence of an O
atom (O1) instead of an S atom (Fig. 3). Atom O1 is involved
Figure 2
Hydrogen bonds stabilizing molecular chains in (I). [Symmetry codes:
(i) ꢁx + 1, ꢁy + 1, ꢁz; (ii) ꢁx + 1, ꢁy + 1, ꢁz + 1.]
Figure 4
Two different views of the three-dimensional hydrogen-bonding network
in (II). The disordered anion H atoms have been omitted for clarity.
Hydrogen bonds are shown with thin lines. (Symmetry codes are as in
Table 3.)
Figure 3
The cation and anion structure in (II). Hydrogen bonds and the
disordered H atom are shown with dashed lines.
+
4ꢁ
o610 Hoły n´ ska and Kubiak
ꢂ
C H
2
N
S and C
H
N
O ꢀHSO
Acta Cryst. (2008). C64, o609–o612
4
4
2
7
4

organic compounds
acceptor, to form anionic chains (Table 3). Similar hydrogen-
bonded anionic chains were described for 1-(diaminomethyl-
ene)thiouron-1-ium hydrogen sulfate by Janczak & Perp e´ tuo
Compound (II)
Crystal data
+
4ꢁ
ꢃ
C
2
H
7
N
4
O ꢀHSO
ꢆ = 78.43 (8)
V = 358.0 (5) A
(2008b). Compound (II) is stabilized by an extensive network
˚
3
M
r
= 200.18
Triclinic, P1
of N—Hꢀ ꢀ ꢀO and O—Hꢀ ꢀ ꢀO hydrogen bonds (Fig. 4). All
amine H atoms from the organic cation are involved in these
hydrogen bonds as donors. Characteristic motifs formed by
the N2—H21ꢀ ꢀ ꢀO11, N1—H1ꢀ ꢀ ꢀO11 and N3—H32ꢀ ꢀ ꢀO41
Z = 2
Mo Kꢂ radiation
˚
˚
˚
a = 6.840 (6) A
b = 7.374 (7) A
ꢁ1
ꢃ = 0.45 mm
T = 100 (2) K
c = 8.019 (4) A
ꢃ
ꢃ
ꢂ = 76.48 (8)
ꢁ = 66.48 (6)
0.35 ꢄ 0.26 ꢄ 0.24 mm
hydrogen bonds could be distinguished. Such motifs, within
1
2
which R (6) rings can be detected, are also present, for
example, in 1-(diaminomethylene)thiouron-1-ium dihydrogen
phosphate and dihydrogen arsenate (Janczak & Perp e´ tuo,
Data collection
Kuma KM-4 CCD diffractometer
Absorption correction: analytical
2901 measured reflections
1633 independent reflections
1530 reflections with I > 2ꢄ(I)
2008b).
(
CrysAlis RED; Oxford
Diffraction, 2006)
min = 0.893, Tmax = 0.904
Rint = 0.017
T
Experimental
HATU (0.5 g) was dissolved in a hydrogen peroxide aqueous solution
(10 ml). An exothermal reaction occurred with evolution of a
Refinement
2
2
R[F > 2ꢄ(F )] = 0.027
wR(F ) = 0.077
111 parameters
H-atom parameters constrained
2
colourless gas. The product was obtained in the form of colourless
crystals on slow evaporation of the reaction mixture. Compounds (I)
and (II) formed when 3 or 30% hydrogen peroxide solutions were
used, respectively. Analysis for (I) found: C 20.7, H 3.3, N 48.1, S
˚
ꢁ3
Áꢅmax = 0.39 e A
S = 1.02
1633 reflections
Áꢅmin = ꢁ0.37 e A˚
ꢁ3
2
8.0%; C
II) found: C 13.1, H 4.3, N 30.9, S 14.4%; C
2.0, H 4.0, N 28.0, S 16.0%.
2
H
4
N
4
S requires: C 20.7, H 3.4, N 48.3, S 27.6%; analysis for
Table 3
Hydrogen-bond geometry (A, ) for (II).
˚
ꢃ
(
2 8 4 5
H N O S requires: C
1
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
Compound (I)
N1—H1ꢀ ꢀ ꢀO11
N2—H21ꢀ ꢀ ꢀO11
N2—H21ꢀ ꢀ ꢀO21
0.87
0.87
0.87
0.87
0.87
0.87
0.87
0.87
0.87
0.87
0.87
0.84
0.84
2.00
2.30
2.48
2.04
2.21
2.53
2.08
1.99
2.40
2.32
2.43
1.73
1.72
2.845 (2)
3.056 (3)
2.963 (2)
2.907 (3)
3.022 (2)
3.052 (4)
2.952 (3)
2.656 (3)
3.067 (3)
3.122 (2)
3.172 (3)
2.558 (3)
2.550 (3)
164
145
116
174
155
119
176
133
134
154
144
168
171
iv
Crystal data
v
N2—H22ꢀ ꢀ ꢀO1
˚
3
i
C
2
4 4
H N S
V = 450.7 (7) A
Z = 4
N3—H31ꢀ ꢀ ꢀO31
N3—H31ꢀ ꢀ ꢀO41
N3—H32ꢀ ꢀ ꢀO41
N4—H41ꢀ ꢀ ꢀO1
N4—H41ꢀ ꢀ ꢀO21
N4—H42ꢀ ꢀ ꢀO11
N4—H42ꢀ ꢀ ꢀO31
M
r
= 116.15
ii
Monoclinic, P2 =n
Mo Kꢂ radiation
1
˚
a = 3.923 (4) A
ꢁ1
ꢃ = 0.56 mm
T = 100 (2) K
˚
iii
i
b = 10.701 (9) A
˚
c = 10.754 (9) A
0.21 ꢄ 0.19 ꢄ 0.18 mm
ꢃ
i
ꢁ
= 93.40 (8)
vi
O21—H211ꢀ ꢀ ꢀO21
vii
Data collection
O31—H311ꢀ ꢀ ꢀO31
Kuma KM-4 CCD diffractometer
3267 measured reflections
960 reflections with I > 2ꢄ(I)
Symmetry codes: (i) x; y; z þ 1; (ii) ꢁx; ꢁy þ 2; ꢁz þ 1; (iii) ꢁx þ 1; ꢁy þ 1; ꢁz þ 1;
(iv) ꢁx þ 1; ꢁy þ 1; ꢁz; (v) ꢁx þ 1; ꢁy; ꢁz þ 1; (vi) ꢁx þ 1; ꢁy þ 2; ꢁz; (vii) ꢁx,
ꢁy þ 2; ꢁz.
Rint = 0.017
1076 independent reflections
Refinement
2
All H atoms were easily found in a difference Fourier map. For (I),
all H-atom positions and isotropic displacement parameters were
˚
refined [N—H = 0.81 (2)–0.86 (2) A]. For (II), DFIX restraints were
2
R[F > 2ꢄ(F )] = 0.025
wR(F ) = 0.060
80 parameters
All H-atom parameters refined
2
˚
ꢁ3
Áꢅmax = 0.30 e A
S = 0.96
1076 reflections
Áꢅmin = ꢁ0.21 e A˚
ꢁ3
used for all N—H bond lengths (0.870 A˚ with an allowed deviation of
˚
0.002 A). Subsequently, the parameters for H atoms involved in
N—H bonds were constrained using the AFIX 3 constraint. The
hydrogen sulfate H atom was found to be disordered over two
positions. Half-occupancy factors were assumed for both positions
and AFIX 147 constraints were used for both disorder components.
All H atoms were refined with Ueq values set at 1.2Ueq(parent atom).
In the final difference maps, the following highest peaks were found:
Table 1
Selected bond lengths (A) for (I).
˚
S1—N4
S1—C1
N1—C1
N1—C2
1.6794 (15)
1.7469 (18)
1.3219 (19)
1.377 (2)
N2—C1
N3—C2
N4—C2
1.3389 (19)
1.3674 (19)
1.3199 (19)
˚
for (I) the maximum is 0.76 A from atom C1, and for (II) the
˚
˚
maximum is 0.69 A from atom O21 and 0.86 A from atom S1.
For both compounds, data collection: CrysAlis CCD (Oxford
Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffrac-
tion, 2006); data reduction: CrysAlis RED; program(s) used to solve
structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine
structure: SHELXL97 (Sheldrick, 2008); molecular graphics:
DIAMOND (Brandenburg & Putz, 2005) and SHELXTL-NT
Table 2
Hydrogen-bond geometry (A, ) for (I).
˚
ꢃ
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
ii
i
N2—H21ꢀ ꢀ ꢀN1
0.86 (2)
0.82 (2)
2.19 (2)
2.18 (2)
3.045 (3)
2.965 (3)
175 (2)
161 (2)
N3—H31ꢀ ꢀ ꢀN4
(Sheldrick, 2008); software used to prepare material for publication:
SHELXL97.
Symmetry codes: (i) ꢁx þ 1; ꢁy þ 1; ꢁz; (ii) ꢁx þ 1; ꢁy þ 1; ꢁz þ 1.
Acta Cryst. (2008). C64, o609–o612
+
4ꢁ
Hoły n´ ska and Kubiak
ꢂ
C H
2
N S and C
4
H N
7
O ꢀHSO
o611
4
2
4

organic compounds
Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262.
Gale, P. A. & Quesada, R. (2006). Coord. Chem. Rev. 250, 3219–3244.
Gimeno, N. & Vilar, R. (2006). Coord. Chem. Rev. 250, 3161–3189.
Hector, D. S. (1889). Chem. Ber. 22, 1176–1180.
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: GD3250). Services for accessing these data are
described at the back of the journal.
Janczak, J. & Perp e´ tuo, G. J. (2008a). Acta Cryst. C64, o114–o116.
Janczak, J. & Perp e´ tuo, G. J. (2008b). Acta Cryst. C64, o330–o334.
Kabir, M. K., Yamada, K., Adachi, K., Kondo, M. & Kawata, S. (2002). Acta
Cryst. E58, m580–m582.
References
Brandenburg, K. & Putz, H. (2005). DIAMOND. Version 3. Crystal Impact
GbR, Bonn, Germany.
Butler, A. R., Edlund, U., Glidewell, C. & Nord e´ n, B. (1986). Acta Chem.
Scand. Ser. B, 40, 779–781.
Butler, A. R., Glidewell, C., Hussain, I. & Maw, P. R. (1980). J. Chem. Res. (S),
pp. 114–115; J. Chem. Res. (M), pp. 1843–1863.
Butler, A. R., Glidewell, C. & Liles, D. C. (1978). Acta Cryst. B34, 3241–3245.
Chakrabarty, K., Kar, T. & Sen Gupta, S. P. (1990). Acta Cryst. C46, 2065–2068.
Cheng, S.-T., Doxiadi, E., Vilar, R., White, A. J. P. & Williams, D. J. (2001). J.
Chem. Soc. Dalton Trans. pp. 2239–2244.
Lankshear, M. D. & Beer, P. D. (2006). Coord. Chem. Rev. 250, 3142–3160.
Lotsch, B. V. & Schnick, W. (2005). Z. Anorg. Allg. Chem. 631, 2967–2969.
Mamaeva, E. A. & Bakibaev, A. A. (2003). Tetrahedron, 59, 7521–7525.
Oxford Diffraction (2006). CrysAlis RED and CrysAlis CCD. Oxford
Diffraction Poland, Wrocław, Poland.
Perp e´ tuo, G. J. & Janczak, J. (2008). Acta Cryst. C64, o264–o268.
Poddar, S. N. & Ray, R. (1952). J. Indian Chem. Soc. 29, 279–290.
Roy, N. K. & Saha, Ch. R. (1980). J. Inorg. Nucl. Chem. 42, 37–42.
Scoponi, M., Polo, E., Bertolasi, V., Carassiti, V. & Bertelli, G. (1991). J. Chem.
Soc. Perkin Trans. 2, pp. 1619–1624.
Chilwana, E. & Simoyi, R. H. (2004). J. Chem. Phys. A, 108, 1024–1032.
Christophersen, C., Ottersen, T., Seff, K. & Treppendahl, S. (1975). J. Am.
Chem. Soc. 97, 5237–5241.
Diaz, P., Mingos, D. M. P., Vilar, R., White, A. J. P. & Williams, D. J. (2004).
Inorg. Chem. 43, 7597–7604.
Doxiadi, E., Vilar, R., White, A. J. P. & Williams, D. J. (2003). Polyhedron, 22,
Senda, H. & Maruha, J. (1985). Acta Cryst. C41, 1329–1331.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Trochimczuk, A. W. & Kolarz, B. N. (2000). Eur. Polym. J. 36, 2359–2363.
Vilar, R., Mingos, D. M. P., White, A. J. P. & Williams, D. J. (1998). Angew.
Chem. Int. Ed. 37, 1258–1261.
Vilar, R., Mingos, D. M. P., White, A. J. P. & Williams, D. J. (1999). Chem.
Commun. pp. 229–230.
2991–2998.
+
4ꢁ
o612 Hoły n´ ska and Kubiak
ꢂ
C H
2
N
S and C
H
N
O ꢀHSO
Acta Cryst. (2008). C64, o609–o612
4
4
2
7
4