M. Mehring
FULL PAPER
213, 3100, 3065 and 2938 cm in compound 2. The bands (31P). IR spectra were obtained with a Bruker FTIR IFS 113v spec-
Ϫ1
3
Ϫ1
Ϫ1
trometer and run as KBr discs. Electrospray ionisation mass spec-
trometric analyses (ESI-MS) were recorded in the positive and the
negative mode with a Thermoquest-Finnigan instrument using
at 3240 cm (3) and 3213 cm (2) are assigned to the
OϪH stretching of a phosphonic acid moiety. No assign-
ment is made for the bands in the region 2938Ϫ3110 cm
which are associated with the OϪH vibration as well as
with the CϪH vibration of 4-(dimethylamino)pyridine.
The thermal stability of compounds 2 and 3 is increased
compared to that of the triphosphonic acid 1. The latter
Ϫ1
MeOH/H
solved in MeOH/H
2
O (1:1) as the mobile phase. The compounds were dis-
O and then diluted with the mobile phase to
2
give solutions of approximate concentration 0.1 m. The samples
were introduced with a syringe pump operating at 10 µL/min. The
capillary voltage was kept at 4.5 kV, while the cone-skimmer volt-
decomposes at 248 °C. The DTA-TG measurements show age was varied in the positive mode between 50 and 110 V, and in
that 3 starts to melt at 265 °C; an exothermic peak at 365 the negative mode between Ϫ70 and Ϫ80 V. The ion source tem-
°
C is indicative of its decomposition. The 1:2 adduct 2 perature was kept at 280 °C. The m/z values reported correspond
to those of the most intense peaks in the corresponding isotope
starts to decompose at 319 °C without prior melting at
lower temperatures.
pattern. Similar ESI-MS spectra of compounds 1Ϫ3 were obtained
in the negative mode. In the positive mode the ESI-MS spectra of
compounds 2 and 3 are dominated by the 4-(dimethylamino)pyridi-
ϩ
2 5 4
nium cation [4-(Me N)C H NH] (m/z ϭ 122.6), but show a simi-
lar peak pattern in the range m/z ϭ 200Ϫ1000 as observed for
compound 1.
Conclusion
The co-crystallisation of 1,3,5-[(HO) (O)P] C H and 4-
2
3
6
3
Graphset Theory:[37] Graphset descriptors indicate the hydrogen
bond motif by the general form Ga,d(n). G describes the structural
unit: C for a chain, D for a finite dimeric system, R for a cyclic
system, S for intramolecular hydrogen bonds. The symbols d and
a define the numbers of hydrogen bond donors and acceptors,
respectively. The symbol n defines the total number of atoms in
a motif.
(dimethylamino)pyridine gives a two-dimensional structure
for the 1:2 adduct 2 and a three-dimensional network for
the 1:1 adduct 3. Although both compounds 2 and 3 are
composed of a large number of different hydrogen bond
patterns, their structures are best described by the assembly
of simple hydrogen-bonded motifs using the graphset the-
ory. In adduct 2 the motifs R2,2(8) and R4,4(16) are inter-
connected to give a one-dimensional ribbon and the ben-
zene spacer connects these ribbons to give a layered struc-
ture. In adduct 3 the R2,3(10) motif is observed solely. Hy-
drogen bonding connects the motif into a layer and the
benzene spacer connects the layers to give a three-dimen-
sional network. This network contains hexagonal channels
1
,3,5-[(HO)
2
(O)P]
3
C
6
H
3
(1): Bromotrimethylsilane (27.9 g,
1
O)
82.03 mmol) was added with a syringe to a solution of 1,3,5-[(iPr-
[36]
2
(O)P]
3
C
6
H
3
2 2
(10.0 g, 18.20 mmol) in 150 mL of CH Cl at 0
°
C. The solution was stirred at room temperature for 12 h and after
the addition of 250 mL of MeOH, the solution was heated at reflux
for 4 h. The solvent was removed in vacuo to give a brownish solid.
Addition of 100 mL of acetonitrile gave a suspension. The solid
which are occupied by 4-(dimethylamino)pyridinium cat- material was filtered off and crystallised from water to give 1 (3.5 g,
ϩ
6 9 9 3
ions, [4-(Me N)C H NH] . Our results demonstrate that 61%) as a colourless solid which decomposes at 248 °C. C H O P
2
5
4
1
(
(
(
1
3
318.1): calcd. C 22.7, H 2.9; found C 22.3, H 2.8. H NMR
the phosphorus counterpart of 1,3,5-(HO C) C H
2
3
6
3
3
3
1
200.13 MHz, [D
4
]MeOH): δ ϭ 8.25Ϫ8.47 (m) ppm. P NMR
(
(
H TMA), the triphosphonic acid 1,3,5-[(HO) (O)P] C H
3 2 3 6
81.02 MHz, [D ]MeOH): δ ϭ 14.1 ppm. ESI-MS (positive mode,
4
1), is a promising building unit in the growing field of
supramolecular chemistry and crystal engineering. In con-
trast to H TMA, it allows the design of 3-D networks. The
extension of the reported work to other amines will add to
the fundamental understanding of the self-assembly process
of phosphonic acids and represents a step towards the
rational design of 3-D hydrogen-bonded frameworks. Fur- (%) ϭ 280.7 (3) [1,3,5-{(HO) (O)P} C H Ϫ 2 H O Ϫ H] , 289.9
thermore, the triphosphonic acid 1 holds potential for the (12) [2 ϫ 1,3,5-{(HO)
ϩ
01 V): m/z (%) ϭ 318.9 (13) [1,3,5-{(HO)
36.6 (8) [1,3,5-{(HO) (O)P} ϩ H O ϩ H] , 350.8 (24)
(O)P} ϩ CH OH ϩ H] , 636.8 (100) [2 ϫ
(O)P}
2 3 6 3
(O)P} C H ϩ H] ,
ϩ
2
3
C
6
H
3
2
3
ϩ
[1,3,5-{(HO)
2
3
C
6
H
3
3
ϩ
1
{
{
,3,5-{(HO)
2
3
C
6
H
3
ϩ
H] , 954.8 (14) [3
H] , 1272.9 (6) [4
ϫ
1,3,5-
1,3,5-
ϩ
(HO)
(HO)
2
(O)P}
(O)P}
3
C
C
6
H
H
3
ϩ
ϫ
ϩ
2
3
6
3
ϩ H] . ESI-MS (negative mode, Ϫ71 V): m/z
Ϫ
2
3
6
3
2
2
Ϫ
2
(O)P}
3 6 3 2
C H Ϫ 3 H O Ϫ 2 H] , 298.7 (22)
Ϫ
[
{
H
CH
1,3,5-{(HO)
2
(O)P}
3
C
6
H
3
Ϫ
Ϫ H O Ϫ H] , 316.8 (100) [1,3,5-
2
preparation of novel three-dimensional metal phosphon-
(HO)
2
(O)P}
3
C
6
H
3
Ϫ H] , 330.8 (17) [1,3,5-{(HO)
2
(O)P}
(O)P}
Ϫ H
3
C
C H
3 6 3
6
H
3
Ϫ
ϩ
ates.
Ϫ
2
O ϩ CH
3
CN Ϫ H] , 348.8 (8) [1,3,5-{(HO)
2
Ϫ
3
Ϫ
CN Ϫ H] , 616.8 (4) [2 ϫ 1,3,5-{(HO)
H] , 634.9 (46) [2 ϫ 1,3,5-{(HO) (O)P} C H
2 3 6 3
2
(O)P}
Ϫ H] . IR (KBr):
ν˜ ϭ 278 (w), 303 (w), 360 (w), 470 (m), 537 (m), 580 (w), 606 (w),
93 (m), 740 (w), 805 (w), 890 (m), 916 (m), 947 (m), 995 (s), 1166
3
C
6
H
3
2
O Ϫ
Ϫ
Experimental Section
6
(
General Remarks: Solvents were distilled from appropriate drying
agents prior to use. Elemental analyses were performed with an
instrument from Carlo Erba Strumentzione (model 1106). Thermal
Ϫ1
s, br.), 1400 (w), 1655 (s, br.), 2325 (s, br.), 3360 (vs, br.) cm .
2 2 2 6 3 2 5 4 2
[1-{(HO) (O)P}-3,5-{(HO)(O) P} C H N)C H NH} ]
]2؊[{4-(Me
؉
analyses were recorded using a vacuum thermoanalyser TA1 from (2): A solution of 4-(dimethylamino)pyridine (385 mg, 3.15 mmol)
Mettler Instrumente AG. The DTA-TG measurements were per-
formed at a heating rate of 6 °C min to a maximum temperature
in 1 mL of MeOH was added to
[(HO) (O)P] (500 mg, 1.57 mmol) in 25 mL of MeOH. A
colourless suspension formed and a mixture of 60 mL of MeOH
and 50 mL of H O was added. The suspension was heated at reflux
0.02 MHz ( P) at room temperature. Chemical shifts δ are given for 10 min and filtered. Colourless crystals of 2 (410 mg, 46%),
a solution of 1,3,5-
Ϫ1
2
3 6 3
C H
of 700 °C in flowing nitrogen using Al
2
O
3
as the reference material.
1
31
1
H and P NMR spectra were recorded at 200.13 MHz ( H) and
2
31
8
1
in ppm and were referenced against Me
4
Si ( H) and 85% H
3
PO
4
which start to decompose at 319 °C, were formed upon slow evap-
3244
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org Eur. J. Inorg. Chem. 2004, 3240Ϫ3246