NCN-chelated organoantimony(III) and organobismuth(III) phosphonates: Syntheses and structures

Article abstract of DOI:10.1002/ejic.200901194

The reactions of the organoantimony and organobismuth oxides [LSbO] ₂ (1) and [LBiO]₂ (2), where L = [2,6(Me ₂NCH₂)₂C₆H₃] ^-, with selected organophosphonic acids in a 1:4 molar ratio gave molecular organoantimony and organobismuth phosphonates LM[OP(R)(O)(OH) ₂ [M = Sb, R = Et (3), Ph (4), tBu (5); M = Bi, R = tBu (8)]. Similarly, the reactions of 1 and 2 with. tBuP(O)(OH)₂ in a 1:2 molar ratio resulted in LM[O₂P(tBu)(O)] [M = Sb (6), M = Bi (9)]. Reactions of 6 and 9 with EtP(O)(OH)₂ yielded mixed phosphonates LM[OP(Et)(O)(OH)][OP(tBu)(O)(OH)J [M = Sb (7), M = Bi (10)]. All Compounds were characterized by elemental analysis, ESI mass spectrometry, ¹H, ¹³C and ³¹P NMR spectroscopy and IR spectroscopy. Molecular structures of compounds 4, 5, 8 and 9 were determined by using X-ray single-crystal diffraction in the solid state. Secondary phosphonates 4, 5 and 8 form weakly bonded dimeric units through hydrogen bridges of the type PO-H...O=P. On the other hand, compound 9 is trimeric in the solid state with the central 12-membered ring formed by three LBi[O₂P(tBu)(O)] building blocks through intermolecular Bi...O=P contacts.

Full text of DOI:10.1002/ejic.200901194

FULL PAPER
DOI: 10.1002/ejic.200901194
NCN-Chelated Organoantimony(III) and Organobismuth(III) Phosphonates:
Syntheses and Structures
[a]
[a]
[a]
[a]
[a]
ˇ
ˇ
˚ˇ ˇ
ˇ
ˇ
Tomás Svoboda, Roman Jambor, Ales Ruzicka, Zdenka Padelková, Milan Erben,
Robert Jirásko,[b] and Libor Dostál*[a]
Keywords: Antimony / Bismuth / Phosphorus / Chelates / X-ray diffraction
The reactions of the organoantimony and organobismuth
oxides [LSbO]2 (1) and [LBiO]2 (2), where [2,6-
(Me2NCH2)2C6H3]–, with selected organophosphonic acids in
compounds were characterized by elemental analysis, ESI
mass spectrometry, 1H, 13C and 31P NMR spectroscopy and
IR spectroscopy. Molecular structures of compounds 4, 5, 8
L
=
a 1:4 molar ratio gave molecular organoantimony and organo- and 9 were determined by using X-ray single-crystal diffrac-
bismuth phosphonates LM[OP(R)(O)(OH)]2 [M = Sb, R = Et
(3), Ph (4), tBu (5); M = Bi, R = tBu (8)]. Similarly, the reactions
of 1 and 2 with tBuP(O)(OH)2 in a 1:2 molar ratio resulted in
LM[O2P(tBu)(O)] [M = Sb (6), M = Bi (9)]. Reactions of 6 and
9 with EtP(O)(OH)2 yielded mixed phosphonates LM[OP-
(Et)(O)(OH)][OP(tBu)(O)(OH)] [M = Sb (7), M = Bi (10)]. All
tion in the solid state. Secondary phosphonates 4, 5 and 8
form weakly bonded dimeric units through hydrogen bridges
of the type PO–H···O=P. On the other hand, compound 9 is
trimeric in the solid state with the central 12-membered ring
formed by three LBi[O2P(tBu)(O)] building blocks through
intermolecular Bi···O=P contacts.
with Ph2P(O)(H) proceeded as a redox reaction, leading to
the formation of Bi–Bi bonds and oxidation of the phos-
phorus atom to the +V state; the corresponding phos-
phonates were isolated.[6]
Introduction
The chemistry organophosphinates and organophos-
phonates of heavier group 15 elements (Sb and Bi) was
studied to some extent in the past,[1] but the number of
isolated and well-defined compounds of this type is still lim-
ited. Nevertheless, it seems that this field has started to re-
vive recently. Mehring et al. reported on the solid-state
structure of the first bismuth phosphonate cluster com-
pound[2] [(tBuPO3)10(tBuPO3H)2Bi14O10·3C6H6·4H2O] pre-
pared by the reaction of BiPh3 with tBuPO3H2 in a 1:1 mo-
lar ratio. The same working group isolated sterically encum-
bered organobismuth phosphinate ArBiBrOP(O)(H)Ar (Ar
denotes the 2,6-Mes-4-tBu-C6H2 ligand) as well.[3] In a sig-
nificant breakthrough, Winpenny et al. succeeded in pre-
paring mixed antimonate–phosphonate compounds by mix-
ing of p-chlorophenylstibonic acid and phenylphosphonic
acid in toluene. The resulting products were, with success,
used as ligands for selected transition metals.[4] A nonanu-
clear organostiboxane cage was isolated by using the
1,1,2,3,3-pentamethyltrimethylene phosphinate as an ancil-
lary ligand recently.[5] The reaction of CNC intramolecu-
larly coordinated organobismuth oxide, containing the
5,6,7,12-tetrahydrodibenz[c,f]-[1,5]azabismocine fragment,
Nevertheless, other well-defined reaction paths for the
preparation of mixed antimony (or bismuth) – phosphorus
oxido compounds are still missing. Recently, we started the
investigation and preparation of well-defined and soluble
organoantimony[7] and organobismuth[8] oxides that hold
potential as starting materials for the preparation of such
mixed main group element oxido compounds by using rela-
tively mild reaction conditions. As part of this investigation,
we report here on the controlled preparation of both anti-
mony and bismuth phosphonates by the reaction of the par-
ent antimony and bismuth oxides [LSbO]2 (1) and [LBiO]2
(2), where L = [2,6-(Me2NCH2)2C6H3]–, with selected or-
ganophosphonic acids. Compounds of the type LM[OP-
(R)(O)(OH)]2 [M = Sb, R = Et (3), Ph (4), tBu (5); M =
Bi, R = tBu (8)] and LM[O2P(tBu)(O)] [M = Sb (6), M
= Bi (9)] were isolated, as were the mixed phosphonates
LM[OP(Et)(O)(OH)][OP(tBu)(O)(OH)] [M = Sb (7), M =
Bi (10)]. All compounds were characterized by elemental
analysis, ESI mass spectrometry, 1H, 13C and 31P NMR
spectroscopy and IR spectroscopy. The molecular struc-
tures of compounds 4, 5, 8 and 9 were determined by using
X-ray single-crystal diffraction in the solid state.
[a] Department of General and Inorganic Chemistry, Faculty of
Chemical Technology, University of Pardubice,
Studentská 573, 53210 Pardubice, Czech Republic
Fax: +420-466037068
Results and Discussion
E-mail: libor.dostal@upce.cz
[b] Department of Analytical Chemistry, Faculty of Chemical
Technology, University of Pardubice,
The reactions of organoantimony oxide 1 with selected
organophosphonic acids in a molar ratio of 1:4 (Scheme 1)
Studentská 573, 53210 Pardubice, Czech Republic
Eur. J. Inorg. Chem. 2010, 1663–1669
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1663

L. Dostál et al.
FULL PAPER
gave, independently of the substituent R on the phosphorus of compounds 7 and 10 was verified on the basis of the ion
atom, secondary phosphonates 3–5 in good yields under formation mechanism. So both the [M – OPO2HEt]+ and
mild reaction conditions (r.t., CH2Cl2). According to the [M – OPO2HtBu]+ ions were detected in the positive-ion
molar ratio used, the acids were not fully deprotonated and mode and the [OPO2HEt]– and [OPO2HtBu]– ions were
each of the phosphorus functionalities carries one POH present in the negative-ion mode (see the Experimental Sec-
acidic hydrogen atom (Scheme 1). Compounds 3–5 are tion). Moreover, some hydrolyzed adducts were observed in
white solids soluble in chlorinated solvents.
the spectra as a result of using water as the solvent.
1
The H and 13C NMR spectra of all secondary phos-
phonates 3–5, 7, 8 and 10 revealed only one set of sharp
signals (singlets) for both the NCH2 and N(CH3)2 groups
at room temperature, indicating symmetrical (tridentate)
coordination of the NCN chelating ligands in all com-
pounds (similarly to the molecular structures determined in
the solid state vide infra). Only one set of signals was ob-
served for the organic substituent of the phosphonate
1
groups in the H and 13C NMR spectra of 3–5, 7, 8 and
10. The 1H NMR spectra also revealed broaden signals
(shifted to lower field) with an integral value of 2, proving
the presence of acidic POH protons in the structure of these
compounds. The 31P NMR spectra showed one sharp signal
in the case of all compounds at δ = 29.3 (3), 15.0 (4), 32.2
(5) and 32.5 ppm (8) (i.e., compounds containing only one
type of phosphonate group). On the contrary, mixed species
7 and 10 displayed two signals in a mutual 1:1 ratio in the
31P NMR spectra at δ = 34.2 and 30.8 ppm for 7 and δ =
32.7 and 29.7 ppm for 10 (reflecting the presence of two
different phosphorus atoms).
Scheme 1. Reactivity of compounds 1 and 2.
The signal of the NCH2 group is observed as an AX
Changing the stoichiometry between 1 and tert-butyl- pattern in the 1H NMR spectrum of 6, and also two singlets
phosphonic acid to 1:2 resulted in complete deprotonation were detected for the N(CH3)2 groups at room temperature.
of the tert-butylphosphonic acid, giving compound 6 as the This indicates, most probably, that the rigid chelating coor-
only isolable product (Scheme 1). This compound can be dination of the phosphonate (as depicted in Scheme 1),
further converted into secondary phosphonate 5 by treat- leading to nonsymmetrical coordination of the central anti-
ment with an additional equivalent of tert-butylphosphonic mony atom, results in nonequivalence of the arms of the
1
acid. More interestingly, if 6 had been reacted with one ligand. The H NMR spectrum of bismuth congener 9 re-
equivalent of ethylphosphonic acid, compound 7 contain- vealed one set of significantly broaden signals for the NCH2
ing two different phosphonates moieties in its structure and N(CH3)2 groups, pointing to a fluxional behaviour of
could be isolated in reasonable yield as the sole product 9 at ambient temperature. In both cases, the signal of the
1
of the reaction. Similar reactions with tert-butylphosphonic acidic POH protons are absent in the H NMR spectra,
acid can be performed by starting from bismuth oxide 2 proving full deprotonation of the tert-butylphosphonic acid
(Scheme 1). In this way, secondary phosphonates 8 and used in the reaction (this was proven by IR spectroscopy
mixed compound 10 were isolated, as was compound 9 pre- vide infra). Only one signal was observed in the 31P NMR
pared by the reaction of 2 with tert-butylphosphonic acid spectra of 6 (δ = 41.0 ppm) and 9 (δ = 35.7 ppm).
in the molar ratio 1:2.
IR spectra were recorded to manifest the presence of the
All compounds were characterized by satisfactory ele- acidic POH moieties in the structure of compounds 3–5, 7,
mental analysis and mass spectrometry (ESI). The most im- 8 and 10. Three broaden bands (around 2700, 2300 and
portant ions observed in the full-scan negative-ion mass 1700 cm–1, see the Experimental Section) were observed for
spectra were [M – H]–, [M + OPO2HtBu]– and [M + each POH group (this means six bands could be found in
OPO2HEt]– detected only for bismuth phosphonates (com- most spectra of the compounds due to the presence of two
pounds 8, 9 and 10). The second mechanism of ion forma- POH groups in their structure). This splitting of the POH
tion observed in the mass spectra of all studied compounds vibration points to a strong hydrogen bonding between
was the cleavage of the most labile bond between Sb (Bi) these POH moieties as demonstrated for other secondary
and the oxygen atom in the phosphonate groups, yielding phosphonates earlier.[9] This presumption was later verified
two complementary ions, where the cationic part of the mo- by the determination of the molecular structure of selected
lecule [M – OPO2HR]+ was present in the positive-ion compounds 4, 5 and 8 in the solid state by X-ray diffraction
mode and the anionic part [OPO2HR]– in the negative-ion (vide infra), where the presence of two crystallographically
mode (R = Et, tBu, Ph). It is also noteworthy that the pres- independent POH groups was established. On the contrary,
ence of two different phosphonate moieties in the structure any bands assignable to the POH vibrations are absent in
1664
www.eurjic.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2010, 1663–1669

NCN-Chelated Organoantimony(III) and Organobismuth(III) Phosphonates
the IR spectra of compounds 6 and 9. In the case of all
compounds 3–10, the presence of the phosphonate func-
tionalities was also corroborated by strong absorption
bands in the PO3 vibration region 1150–950 cm–1 (see the
Experimental Section).
The solid-state molecular structures of compounds 4, 5,
8 and 9 were determined by X-ray single-crystal diffraction.
The molecular structures of both organoantimony phos-
phonates 4 and 5 are closely structurally related (Figures 1
and 2).
Figure 2. ORTEP diagram of compound 5 with thermal displace-
ment parameters at 30% probability; hydrogen atoms, except those
involved in hydrogen bonds, are omitted for clarity. Symmetry op-
erator a = 1 – x, –y, –z. Selected distances [Å] and angles [°]: Sb1–
C1 2.092(8), Sb1–N1 2.385(7), Sb1–N2 2.464(8), Sb1–O1 2.204(5),
Sb1–O4 2.184(5), O2–O5a 2.495(9), O3–O6a 2.517(8), C1–Sb1–N1
74.6(3), C1–Sb1–N2 74.03, C1–Sb1–O1 81.2(3), C1–Sb1–O4
83.5(3), N1–Sb1–N2 148.3(3), O1–Sb1–O4 164.6(2), O2–H(O2)–
O5a 153, O3–H(O6a)–O6a 168.
bonding with the P=O oxygen atoms O5a and O3a from
the neighbouring molecule [the bond lengths O2–O5a and
O6–O3a are, respectively, 2.477(2) and 2.508(5) Å for 4 and
2.495(9) and 2.517(8) Å for 5, the bonding angles O2–
H(O2)–O5a and O6–H(O6)–O3a are, respectively, 170 and
156° for 4 and 153 and 168° for 5]. This hydrogen bonding
is also answered by the POH groups from the second mole-
cule, leading to four PO–H···O=P bridges and the forma-
tion of a dimeric structure.
The molecular structure of bismuth secondary phos-
phonate 8 is similar to that of its antimony congeners (Fig-
ure 3). The NCN chelating ligand coordinates the bismuth
atom in a tridentate fashion with Bi–N bond lengths of
2.510(5) and 2.500(5) Å and a bonding angle N1–Bi1–N2
of 146.17(17)°. The oxygen atoms of the phosphonate
groups are located mutually in trans positions [the bonding
angle O1–Bi1–O4 equals 162.62(14)°]. The coordination
Figure 1. ORTEP diagram of compound 4 with thermal displace-
ment parameters at 30% probability; hydrogen atoms, except those
involved in hydrogen bonds, are omitted for clarity. Symmetry op-
erator a = 2 – x, 1 – y, 1 – z. Selected distances [Å] and angles
[°]: Sb1–C1 2.103(3), Sb1–N1 2.454(3), Sb1–N2 2.396(3), Sb1–O1
2.198(3), Sb1–O4 2.229(3), O2 – O5a 2.477(2), O3 – O6a 2.508(5),
C1–Sb1–N1 74.31(13), C1–Sb1–N2 74.73(13), C1–Sb1–O1
83.11(12), C1–Sb1–O4 81.94(12), N1–Sb1–N2 149.04(12), O1–
Sb1–O4 164.93(10), O2–H(O2)–O5a 170, O3–H(O6a)–O6a 156.
In both cases, the central antimony atom is coordinated polyhedron of the central atom might be described as a dis-
by the NCN chelating ligand in a tridentate fashion [the torted tetragonal pyramid. Compound 8 forms a similar di-
range of the Sb–N bond lengths in 4 and 5 is 2.385(7)– meric structure, as determined for compounds 4 and 5,
2.464(8) Å]. The coordination polyhedron around the cen- through linking two neighbouring molecules through hy-
tral atom can be described as a strongly distorted tetragonal drogen bridges between the O2–O5a atoms [2.533(6) Å,
pyramid with the ipso carbon atom C1 occupying the apical bonding angle 168°] and the O6–O3a atoms [2.541(6) Å,
position. The basal plane is formed by two nitrogen atoms bonding angle 172°].
N1 and N2 [the bonding angle N1–Sb–N2 is 149.04(12)°
The hydrogen bonds seem to be nearly equivalent in all
for 4 and 148.3(3)° for 5] and two oxygen atoms O1 and O4 secondary phosphonates 4, 5 and 8, as demonstrated by
[the range of the Sb–O bond lengths in 4 and 5 is 2.184(5)– the respective oxygen–oxygen bond lengths, although these
2.229(3) Å, the bonding angle O1–Sb1–O4 equals become a bit longer along this set of compounds for 4
164.93(10)° for 4 and 164.6(2)° for 5]. As established for 4 [2.477(2), 2.508(5) Å], for 5 [2.495(9), 2.517(8) Å] and for 8
and 5 in solution, each of the coordinated phosphonate [2.553(6), 2.541(6) Å]. It is also noteworthy that one of the
groups carries one POH moiety (oxygen atoms O2 and O6). hydrogen bonds is in all cases shorter than the second one.
These functionalities are involved in effective hydrogen This is particularly evident in compound 4. The hydrogen
Eur. J. Inorg. Chem. 2010, 1663–1669
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1665

L. Dostál et al.
FULL PAPER
bonds in 4, 5 and 8 are shorter in comparison with the
hydrogen bonds found in the organophosphonic acids (i.e.,
2.541–2.646 Å in tert-butylphosphonic acid and 2.546–
2.607 Å in phenylphosphonic acid).[10]
The molecular structure of compound 9 is depicted in
Figure 4. As postulated in solution (vide supra), the phos-
phonate groups in 9 are fully deprotonated and are coordi-
nated to the central metal Bi1 in a chelating mode [oxygen
atoms O25 and O25d, the Bi–O bond lengths are
2.518(8) Å]. The third oxygen atom O5b of the same phos-
phonate group is involved in a intermolecular connection
with the bismuth atom Bi1b of the neighboring molecule
[the Bi–O bond length is 2.313(17) Å]. This bonding situa-
tion is repeated for other molecules as well, leading to a
trimeric structure built up from three LBi[O2P(tBu)(O)]
subunits (Figure 4) and closure of the 12-membered ring.
The organic groups, that is, ligands L and the tBu groups,
are arranged alternately along this core and are orientated
Figure 3. ORTEP diagram of compound 8 with thermal displace-
ment parameters at 30% probability; hydrogen atoms, except those
involved in hydrogen bonds, are omitted for clarity. Symmetry op-
erator a = –x, –y, 1 – z. Selected distances [Å] and angles [°]: Bi1– outside the central ring. The pendant arms of the ligands
C1 2.177(6), Bi1–N1 2.510(5), Bi1–N2 2.500(5), Bi1–O1 2.353(4),
are located above and below the ring and are coordinated
Bi1–O4 2.270(4), O2–O5a 2.553(6), O3–O6a 2.541(6), C1–Bi1–N1
to the bismuth atoms. This tridentate coordination of the
72.6(2), C1–Bi1–N2 73.60(19), C1–Bi1–O1 79.12(19), C1–Bi1–O4
central metals by the ligands L [the Bi–N bond lengths are
83.62(18), N1–Bi1–N2 146.17(17), O1–Bi1–O4 162.62(14), O2–
2.60(2) Å, the bonding angle N1–Sb–N2 is 136.2(8)°] leads
to an increase in the coordination number of the bismuth
atom to six. The coordination polyhedron around the bis-
muth may be described as a distorted pentagonal pyramid
and the shapes of the coordination polyhedra around the
phosphorus atoms remain essentially tetrahedral.
H(O2)–O5a 168, O3–H(O6a)–O6a 172.
Conclusions
In conclusion, we have demonstrated that NCN-chelated
antimony and bismuth oxides 1 and 2 are useful starting
materials for the preparation of the corresponding phos-
phonates. The reaction of 1 and 2 with selected organo-
phosphonic acids gave, in a controlled and predictable man-
ner, depending on the molar ratio, either the secondary
phosphonates 3–5 and 8 or fully deprotonated phosphon-
ates 6 and 9. Compounds 3–5 and 8 contain in their struc-
ture two acidic POH hydrogen atoms that are promising in
regard to the investigation of their further reactivity.
Furthermore, phosphonates 6 and 8 react with ethylphos-
phonic acid with formation of mixed compounds 7 and 10
containing two different organic groups on the phosphorus
atoms, interestingly, without any evidence for scrambling of
these ligands. These findings make compounds 6 and 9 pos-
sible precursors for the preparation of other mixed com-
pounds containing either three different main group central
atoms or mixed antimony (bismuth) phosphonate – phos-
Figure 4. ORTEP diagram of compound 9 with thermal displace-
ment parameters at 30% probability and view of the central ring phinate compounds. This investigation is currently un-
system. The disordered ligands (except the nitrogen donor atoms
derway in our laboratory.
and the ipso carbon atoms) and the hydrogen atoms are omitted
for clarity. Symmetry operators a = 1 – y, x – y, z; b = 1 – x + y,
1 – x, z; c = 1 – x + y, 1 – y, 1/2 – z; d = x, y, 1/2 – z; e = 1 – y,
Experimental Section
x – y, 1/2 – z. Selected distances [Å] and angles [°]: Bi1–C1
2.178(11), Bi1–N17 2.60(2), Bi1–O5 2.313(17), Bi1–O25 2.518(8),
C1–Bi1–N17 71.4(6), C1–Bi1–O5 89.8(5), C1–Bi1–O25 88.5(3),
N17–Bi1–N17d 136.2(8), N17–Bi1–O5 78.7(4), N17–Bi1–O25d
1
General Procedures: H, 13C and 31P NMR spectra were recorded
with a Bruker AMX360 spectrometer, by using a 5-mm tunable
73.1(5).
broad-band probe. Appropriate chemical shifts in 1H and 13C
1666
www.eurjic.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2010, 1663–1669

NCN-Chelated Organoantimony(III) and Organobismuth(III) Phosphonates
NMR spectra were related to the residual signals of the solvent
[CDCl3: δ(1H) = 7.27 ppm and δ(13C) = 77.23 ppm]. The 31P NMR
spectra were related to external 85% H3PO4 δ(31P) = 0.00 ppm.
Positive-ion and negative-ion electrospray ionization (ESI) mass
spectra were measured with an ion trap analyzer Esquire 3000
(Bruker Daltonics, Bremen, Germany) in the range m/z = 50–1000.
The samples were dissolved in a mixture of acetonitrile/water (1:1)
and analyzed by direct infusion at a flow rate of 5 µLmin–1. The
ion source temperature was 300 °C, the tuning parameter com-
and tert-butylphosphonic acid (286 mg, 2.07 mmol) in dichloro-
methane (15 mL) gave 5 as white crystals (417 mg, 73%). M.p.
300 °C (decomp.). MS (ESI+): m/z (%)
=
777 (27)
[L2Sb2O(OPO2HtBu)]+, 449 (28) [M – OPO2HtBu]+, 329 (100)
[LSbOH]+. MS (ESI–): m/z (%) = 275 (99) [2HOPO2HtBu – H]–,
1
137 (100) [OPO2HtBu]–. H NMR (360 MHz, CDCl3, 25 °C): δ =
3
0.98 [d, JP,H = 18 Hz, 18 H, PC(CH3)3], 2.88 [s, 12 H, N(CH3)2],
3.99 (s, 4 H, NCH2), 7.19 (d, 2 H, Ar-H3,5), 7.36 (t, 1 H, Ar-H4),
11.10 (br. s, 2 H, POH) ppm. 13C NMR (90.56 MHz, CDCl3,
1
pound stability was 100% and the flow rate and the pressure of 25 °C): δ = 25.6 [s, PC(CH3)3], 31.2 [d, JP,C = 143 Hz, PC(CH3)3],
nitrogen were 4 Lmin–1 and 10 psi, respectively. Infrared spectra
were recorded in the range 4000–400 cm–1 as KBr pellets or Nujol
mulls with an FTIR spectrometer Nicolet Magna 550. The starting
compounds ethylphosphonic acid (98%), phenylphosphonic acid
(98%) and tert-butylphosphonic acid (98%) were obtained from
commercial suppliers and used as delivered. The compounds [2,6-
46.4 [s, N(CH3)2], 64.3 (s, NCH2), 125.5 (s, Ar-C3,5), 128.4 (s, Ar-
C4), 143.6 (s, Ar-C2,6), 157.7 (s, Ar-C1) ppm. 31P NMR
(145.79 MHz, CDCl , 25 °C): δ = 32.2 (s) ppm. IR: ν = 2725 (s),
˜
3
2679 (m), 2385 (m), 2330 (m), 1672 (br. m, POH), 1130 (s), 1091
(vs), 1033 (s), 1001 (vs), 985 (vs, PO3) cm–1. C20H39N2O6P2Sb
(587.24): calcd. C 40.9, H 6.7; found C 41.2, H 6.8.
[7]
[8]
(Me2NCH2)2C6H3SbO]2 (1) and [2,6-(Me2NCH2)2C6H3BiO]2
(2) were prepared according to literature procedures.
2,6-(Me2NCH2)2C6H3Sb[O2P(O)tBu] (6):
A solution of [2,6-
(Me2NCH2)2C6H3SbO]2 (1; 114 mg, 0.156 mmol) in dichlorometh-
ane (10 mL) was added to a suspension of tert-butylphosphonic
acid (43 mg, 0.31 mmol) in dichloromethane (15 mL), and the re-
sulting mixture was stirred for an additional 3 h at the room tem-
perature. The reaction mixture was evaporated in vacuo, and the
residue was washed with hexane (5 mL). The remaining white solid
was extracted with toluene (10 mL). The toluene filtrate was evapo-
rated to give 6 as white crystals (95 mg, 68%). M.p. 179–181 °C.
MS (ESI+): m/z (%) = 777 (100) [L2Sb2O(OPO2HtBu)]+, 449 (5)
[M + H]+, 329 (86) [LSbOH]+. MS (ESI–): m/z (%) = 275 (28)
2,6-(Me2NCH2)2C6H3Sb[OP(O)(OH)Et]2 (3): A solution of [2,6-
(Me2NCH2)2C6H3SbO]2 (1; 100 mg, 0.152 mmol) in dichlorometh-
ane (10 mL) was added to a suspension of ethylphosphonic acid
(67 mg, 0.61 mmol) in dichloromethane (15 mL), and the resulting
mixture was stirred for an additional 2 h at room temperature. The
reaction mixture was evaporated in vacuo, and the residue was
washed with hexane (5 mL). The remaining white solid was recrys-
tallized from dichloromethane/hexane to give 3 as white crystals
(116 mg, 72%). M.p. 203–205 °C. MS (ESI+): m/z (%) = 749 (55)
[L2Sb2O(OPO2HEt)]+, 421 (19) [M – OPO2HEt]+, 329 (100)
[LSbOH]+. MS (ESI–): m/z (%) = 219 (100) [2HOPO2HEt – H]–,
109 (16) [OPO2HEt]–. 1H NMR (360 MHz, CDCl3, 25 °C): δ =
0.99 (m, 6 H, PCH2CH3), 1.46 (m, 4 H, PCH2CH3), 2.85 [s, 12 H,
N(CH3)2], 4.00 (s, 4 H, NCH2), 7.20 (d, 2 H, Ar-H3,5), 7.34 (t, 1
H, Ar-H4), 11.55 (br. s, 2 H, POH) ppm. 13C NMR (90.56 MHz,
[2HOPO2HtBu
–
H]–, 137 (100) [OPO2HtBu]–. 1H NMR
3
(360 MHz, CDCl3, 25 °C): δ = 0.93 [d, JP,H = 15Hz, 9 H,
PC(CH3)3], 2.13 [s, 6 H, N(CH3)2], 2.73 [s, 6 H, N(CH3)2], 3.39 and
2
4.43 (AX pattern, JH,H = 14 Hz, 4 H, NCH2), 7.13 (d, 2 H, Ar-
H3,5), 7.31 (t, 1 H, Ar-H4) ppm. 13C NMR (90.56 MHz, CDCl3,
25 °C): δ = 25.9 [s, PC(CH3)3], 31.3 [d, J1 = 129 Hz, PC(CH3)3],
P,C
1
CDCl3, 25 °C): δ = 7.6 (s, PCH2CH3), 20.8 (d, JP,C = 142 Hz,
42.5 [s, N(CH3)2], 45.7 [s, N(CH3)2], 63.2 (s, NCH2), 125.6 (s, Ar-
PCH2CH3), 46.3 [s, N(CH3)2], 64.3 (s, NCH2), 124.9 (s, Ar-C3,5),
C3,5), 130.6 (s, Ar-C4), 146.8 (s, Ar-C2,6), 152.6 (s, Ar-C1) ppm.
129.5 (s, Ar-C4), 143.8 (s, Ar-C2,6), 157.0 (s, Ar-C1) ppm. 31P
31P NMR (145.79 MHz, CDCl , 25 °C): δ = 41.0 (s) ppm. IR: ν =
˜
3
NMR (145.79 MHz, CDCl , 25 °C): δ = 29.3 (s) ppm. IR: ν = 2723
˜
1132 (s), 1095 (vs), 1031 (m), 1001 (m), 987 (s, PO3) cm–1.
3
(m), 2389 (m), 2328 (m), 1738 (m), 1676 (s, POH), 1136 (vs), 1099
(vs), 1036 (vs), 987 (vs, PO3) cm–1. C16H31N2O6P2Sb (531.13):
calcd. C 36.2, H 5.9; found C 36.3, H 6.2.
C16H28N2O3PSb (449.14): calcd. C 42.8, H 6.3; found C 42.9, H
6.4.
2,6-(Me2NCH2)2C6H3Sb[OP(O)(OH)tBu][OP(O)(OH)Et] (7):
A
2,6-(Me2NCH2)2C6H3Sb[OP(O)(OH)Ph]2 (4): Prepared by a pro-
cedure similar to that described for compound 3. [2,6-(Me2NCH2)2-
C6H3SbO]2 (1; 95 mg, 0.14 mmol) in dichloromethane (10 mL) and
phenylphosphonic acid (91 mg, 0.58 mmol) in dichloromethane
(15 mL) gave 4 as white crystals (135 mg, 75%). M.p. 234–237 °C.
MS (ESI+): m/z (%) = 797 (20) [L2Sb2O(OPO2HPh)]+, 469 (3) [M –
OPO2HPh]+, 329 (100) [LSbOH]+. MS (ESI–): m/z (%) = 315 (14)
solution of 6 (68 mg, 0.15 mmol) in dichloromethane (20 mL) was
added to a suspension of ethylphosphonic acid (17 mg, 0.15 mmol)
in dichloromethane (15 mL), and the resulting mixture was stirred
for an additional 1 h at room temperature. The reaction mixture
was evaporated in vacuo, and the residue was washed with hexane
(5 mL). The remaining white solid was recrystallized from dichloro-
methane/hexane to give 7 as white crystals (60 mg, 71%). M.p.
237 °C (decomp.). MS (ESI+): m/z (%) = 449 (4) [M – OPO2-
HEt]+, 421 (2) [M – OPO2HtBu]+, 329 (100) [LSbOH]+. MS (ESI–
): m/z (%) = 137 (100) [OPO2HtBu]–, 109 (16) [OPO2HEt]–. 1H
1
[2HOPO2HPh – H]–, 157 (100) [OPO2HPh]–. H NMR (360 MHz,
CDCl3, 25 °C): δ = 2.75 [s, 12 H, N(CH3)2], 4.01 (s, 4 H, NCH2),
6.78 (br. s, 2 H, POH), 7.23 (m, 6 H, Ph-H3,4,5), 7.32 (d, 2 H, Ar-
H3,5), 7.39 (t, 1 H, Ar-H4), 7.52 (m, 4 H, Ph-H2,6) ppm. 13C NMR
(90.56 MHz, CDCl3, 25 °C): δ = 46.2 [s, N(CH3)2], 64.3 (s, NCH2),
3
NMR (360 MHz, CDCl3, 25 °C): δ = 0.93 [d, JP,H = 9 Hz, 9 H,
PC(CH3)3], 0.99 (m, 3 H, PCH2CH3) – overlap with the signal of
the PC(CH3)3 group, 1.40 (m, 2 H, PCH2CH3), 2.82 [s, 12 H,
N(CH3)2], 3.95 (s, 4 H, NCH2), 7.14 (d, 2 H, Ar-H3,5), 7.29 (t, 1
H, Ar-H4), 11.63 (br. s, 2 H, POH) ppm. 13C NMR (90.56 MHz,
3
125.2 (s, Ar-C3,5), 127.8 (d, JP,C = 14 Hz, Ph-C3,5), 130.0 (s, Ar-
2
C4), 130.1 (s, Ph-C4), 130.6 (d, JP,C = 10 Hz, Ph-C2,6), 135.5 (d,
1JP,C = 187 Hz, Ph-C1), 144.3 (s, Ar-C2,6), 156.2 (s, Ar-C1) ppm.
31P NMR (145.79 MHz, CDCl , 25 °C): δ = 15.0 (s) ppm. IR: ν =
˜
3
1
CDCl3, 25 °C): δ = 7.6 (s, PCH2CH3), 21.3 (d, JP,C = 143 Hz,
2723 (m), 2686 (m), 2385 (m), 2318 (s), 1670 (s, POH), 1134 (vs),
1093 (vs), 1001 (vs), 950 (vs), 957 (vs, PO3) cm–1. C24H31N2O6P2Sb
(627.22): calcd. C 46.0, H 5.0; found C 46.1, H 5.2.
1
PCH2CH3), 25.5 [s, PC(CH3)3], 30.6 [d, JP,C
= 142 Hz,
PC(CH3)3], 46.4 [s, N(CH3)2], 64.4 (s, NCH2), 124.9 (s, Ar-C3,5),
129.5 (s, Ar-C4), 143.9 (s, Ar-C2,6), 157.2 (s, Ar-C1) ppm. 31P
2,6-(Me2NCH2)2C6H3Sb[OP(O)(OH)tBu]2 (5): Prepared by a pro- NMR (145.79 MHz, CDCl , 25 °C): δ = 34.2, 30.8 ppm. IR: ν =
˜
3
cedure similar to that described for compound 3. [2,6-(Me2NCH2)2-
2730 (m), 2707 (br. m), 2386 (br. m), 2330 (br. m), 1733 (s), 1668
C6H3SbO]2 (1; 340 mg, 0.517 mmol) in dichloromethane (10 mL) (s, POH), 1133 (vs), 1099 (vs), 1033 (vs), 999 (vs, PO3) cm–1.
Eur. J. Inorg. Chem. 2010, 1663–1669
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1667

L. Dostál et al.
C18H35N2O6P2Sb (559.18): calcd. C 38.7, H 6.3; found C 38.9, H applied for all crystals. The structures were solved by the direct
FULL PAPER
6.5.
methods (SIR92)[12] and refined by a full-matrix least-squares pro-
cedure based on F2 (SHELXL97).[13] Hydrogen atoms were fixed
into idealized positions (riding model) and assigned temperature
factors Hiso(H) = 1.2Ueq (pivot atom) or of 1.5Ueq for the methyl
moiety with C–H = 0.96, 0.97 and 0.93 Å for methyl, methylene
and hydrogen atoms in the aromatic ring, respectively, and 0.83 Å
for the O–H bonds. The final difference maps for 4, 5 and 8 dis-
played no peaks of chemical significance, as the highest peaks and
holes are in close vicinity (≈1 Å) to the heavy atoms. In 9, there is
a large peak (≈4 eA–3) that has no chemical significance, and even
after use of different software techniques (Platon-SQUEEZE) in
order to explain it, no better model was obtained. In the same
crystal, all phenyl rings of the NCN chelating ligands are disor-
dered. These were split into three approximately equivalent posi-
tions; nevertheless, the positions of all heavier atoms, including the
whole phosphonate groups, were well modelled.
2,6-(Me2NCH2)2C6H3Bi[OP(O)(OH)tBu]2 (8): Prepared by a pro-
cedure similar to that described for compound 3. [2,6-(Me2NCH2)2-
C6H3BiO]2 (2; 443 mg, 0.532 mmol) in dichloromethane (10 mL)
and tert-butylphosphonic acid (295 mg, 2.13 mmol) in dichloro-
methane (15 mL) gave 8 as white crystals (467 mg, 65%). M.p.
Ͼ350 °C. MS (ESI+): m/z (%) = 537 (100) [M – OPO2HtBu]+, 417
(77) [LBiOH]+. MS (ESI–): m/z (%) = 811 (8) [M+OPO2HtBu]–,
673 (21) [M – H]–, 137 (100) [OPO2HtBu]–. H NMR (360 MHz,
CDCl3, 25 °C): δ = 0.99 [d, JP,H = 16 Hz, 18 H, PC(CH3)3], 2.90
1
3
[s, 12 H, N(CH3)2], 4.26 (s, 4 H, NCH2), 7.47 (t, 1 H, Ar-H4),
7.65 (d, 2 H, Ar-H3,5), 10.37 (br. s, 2 H, POH) ppm. 13C NMR
1
(90.56 MHz, CDCl3, 25 °C): δ = 25.7 [s, PC(CH3)3], 31.3 [d, JP,C
= 141 Hz, PC(CH3)3], 46.4 [s, N(CH3)2], 67.8 (s, NCH2), 127.6 (s,
Ar-C3,5), 129.0 (s, Ar-C4), 151.6 (s, Ar-C2,6) ppm, (Ar-C1) not
observed. 31P NMR (145.79 MHz, CDCl3, 25 °C): δ = 32.5 (s) ppm.
CCDC-755837 (for 8), -755838 (for 5), -755839 (for 4) and -755840
(for 9) contain the supplementary crystallographic data for this pa-
per. These data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_
request/cif.
IR: ν = 2726 (m), 2671 (m), 2387 (br. s), 2329 (br. m), 1732 (s),
˜
1662 (m, POH), 1128 (s), 1101 (vs), 1029 (s), 1001 (s), 989 (vs, PO3)
cm–1. C20H39BiN2O6P2 (674.47): calcd. C 35.6, H 5.8; found C 35.7,
H 5.9.
2,6-(Me2NCH2)2C6H3Bi[O2P(O)tBu] (9): Prepared by a procedure
similar to that described for compound 6. [2,6-(Me2NCH2)2-
C6H3BiO]2 (2; 495 mg, 0.60 mmol) in dichloromethane (15 mL)
and tert-butylphosphonic acid (164 mg, 1.19 mmol) in dichloro-
methane (15 mL) gave 9 as white crystals (306 mg, 48%). M.p.
292 °C (decomp.). MS (ESI+): m/z (%) = 537 (55) [M + H]+, 417
(100) [LBiOH]+. MS (ESI–): m/z (%) = 673 (15) [M + OPO2-
HtBu]–, 571 (15) [M + Cl]–, 137 (100) [OPO2HtBu]–. 1H NMR
(360 MHz, CDCl3, 25 °C): δ = 0.47 (v br. s, 9 H), 2.75 [br. s, 12 H,
N(CH3)2], 4.24 (br. s, 4 H, NCH2), 7.39 (t, 1 H, Ar-H4), 7.52 (d, 2
H, Ar-H3,5) ppm. 31P NMR (145.79 MHz, CDCl3, 25 °C): δ = 35.7
Crystallographic Data for 4: C24H31N2O6P2Sb, M = 627.20, tri-
¯
clinic, P1, a = 9.60110(6) Å, b = 10.8722(6) Å, c = 12.6439(5) Å, α
= 87.654(4)°, β = 88.544(5)°, γ = 84.612(5)°, V = 1312.57(12) Å3,
Z = 2, T = 150(1) K, 24003 total reflections, 5987 independent [Rint
= 0.054, R1 (obs. data) = 0.039, wR2 (all data) 0.091].
Crystallographic Data for 5: C21H41Cl2O6N2P2Sb, M = 627.15, tri-
¯
clinic, P1, a = 8.5612(5) Å, b = 13.3846(3) Å, c = 14.6761(12) Å, α
= 69.384(4)°, β = 83.020(7)°, γ = 80.004(5)°, V = 1546.79(16) Å3,
Z = 2, T = 150(1) K, 27187 total reflections, 7040 independent [Rint
= 0.386, R1 (obs. data) = 0.077, wR2 (all data) 0.160].
(s) ppm. IR: ν = 1089 (m), 1062 (vs), 1031 (s), 1014 (s), 950 (vs,
˜
Crystallographic Data for 8: C20H39N2O6P2Bi, M = 674.045, mono-
PO3) cm–1. C16H28BiN2O3P (536.37): calcd. C 35.8, H 5.3; found
C 35.6, H 5.5.
clinic, P21/c,
a = 9.6582(4) Å, b = 14.8608(10) Å, c =
18.3442(12) Å, β = 90.251(4)°, V = 2632.8(3) Å3, Z = 4, T =
150(1) K, 25111 total reflections, 5999 independent [Rint = 0.114,
R1 (obs. data) = 0.048, wR2 (all data) 0.079].
2,6-(Me2NCH2)2C6H3Bi[OP(O)(OH)tBu][OP(O)(OH)Et]
(10):
Prepared by a procedure similar to that described for compound 7.
Compound 9 (61 mg, 0.11 mmol) in dichloromethane (20 mL) and
ethylphosphonic acid (13 mg, 0.11 mmol) in dichloromethane
(15 mL) gave 10 as a white solid (53 mg, 72%). M.p. 279 (decomp.).
MS (ESI+): m/z (%) = 537 (100) [M – OPO2HEt]+, 509 (25) [M –
OPO2HtBu]+, 417 (15) [LBiOH]+. MS (ESI–): m/z (%) = 783 (32)
[M + OPO2HtBu]–, 755 (16) [M + OPO2HEt]–, 645 (18) [M – H]–,
137 (100) [OPO2HtBu]–, 109 (15) [OPO2HEt]–. 1H NMR
Crystallographic Data for 9: C48H84N6O9P3Bi3, M = 1609.06, hex-
agonal, P63/m, a = 17.1000(19) Å, b = 17.1000(19) Å, c =
14.5642(7) Å, V = 3688.1(6) Å3, Z = 2, T = 150(1) K, 20587 total
reflections, 2919 independent [Rint = 0.136, R1 (obs. data) = 0.069,
wR2 (all data) 0.24].
3
(360 MHz, CDCl3, 25 °C): δ = 0.98 [d, JP,H = 9 Hz, 9 H,
Acknowledgments
PC(CH3)3], 0.98 (m, 3 H, PCH2CH3) – overlap with the signal of
the PC(CH3)3 group, 1.47 (m, 2 H, PCH2CH3), 2.90 [s, 12 H, The authors would like to thank the Grant Agency of the Czech
N(CH3)2], 4.28 (s, 4 H, NCH2), 7.48 (t, 1 H, Ar-H4), 7.65 (d, 2 H, Republic (P106/10/0443) and the Ministry of Education of the
Ar-H3,5), 11.00 (br. s, 2 H, POH) ppm. 13C NMR (90.56 MHz, Czech Republic (MSM0021627501 and LC523) for financial sup-
1
CDCl3, 25 °C): δ = 8.2 (s, PCH2CH3), 21.8 (d, JP,C = 139 Hz, port. R. Jirásko acknowledges the support of the Ministry of Edu-
1
PCH2CH3), 25.9 [s, PC(CH3)3], 31.5 [d, JP,C = 141 Hz, PC- cation, Youth and Sports of the Czech Republic
(CH3)3], 46.5 [s, N(CH3)2], 68.1 (s, NCH2), 127.8 (s, Ar-C3,5), 129.1 (MSM0021627502).
(s, Ar-C4), 151.6 (s, Ar-C2,6) ppm. (s, Ar-C1) not observed. 31P
NMR (145.79 MHz, CDCl , 25 °C): δ = 32.7, 29.7 ppm. IR: ν =
˜
3
[1] a) G. E. Graves, J. R. van Wazer, J. Organomet. Chem. 1978,
150, 233–237; b) G. E. Graves, J. R. van Wazer, J. Organomet.
Chem. 1977, 131, 31–34; c) C. Silvestru, A. Silvestru, I. Haiduc,
D. B. Sowerby, K. H. Ebert, H. J. Breunig, Polyhedron 1997,
16, 2643–2649 and references cited therein; d) M. A. Said,
K. C. K. Swamy, D. M. Poojary, A. Clearfield, M. Veith, V.
Huch, Inorg. Chem. 1996, 35, 3235–3241; e) M. N. Gibbons,
D. B. Sowerby, J. Chem. Soc., Dalton Trans. 1997, 2785–2792;
f) M. A. Said, K. C. K. Swamy, K. Babu, K. Aparna, M. Ne-
thaji, J. Chem. Soc., Dalton Trans. 1995, 2151–2157.
2726 (m), 2667 (m), 2391 (s), 2323 (s), 1735 (s), 1654 (br. s, POH),
1099 (vs), 1022 (vs, PO3) cm–1. C18H35BiN2O6P2 (660.44): calcd. C
34.6, H 5.7; found C 34.7, H 5.9.
X-ray Crystallography: Suitable single crystals of 4, 5, 8 and 9 were
mounted on a glass fibre with oil and measured with a four-circle
diffractometer KappaCCD instrument with a CCD area detector
and monochromated Mo-Kα radiation (λ = 0.71073 Å) at 150(1) K.
The numerical[11] absorption corrections from crystal shape were
1668
www.eurjic.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2010, 1663–1669

NCN-Chelated Organoantimony(III) and Organobismuth(III) Phosphonates
ˇ
[2] M. Mehring, M. Schürmann, Chem. Commun. 2001, 2354–
2355.
[3] H. J. Breunig, N. Haddad, E. Lork, M. Mehring, C. Mügge,
C. Nolde, C. I. Rat, M. Schürmann, Organometallics 2009, 28,
1202–1211.
[4] a) S. Ali, V. Baskar, C. A. Muryn, R. E. P. Winpenny, Chem.
Commun. 2008, 6375–6377; b) S. Ali, C. A. Muryn, F. Tuna,
R. E. P. Winpenny, Dalton Trans. 2010, 39, 124–131.
[5] V. Chandrasekhar, R. Thirumoorthi, Organometallics 2009, 28,
2637–2639.
[9] V. Koleva, V. Stefov, A. Cahil, M. Najdoski, B. Soptrajanov, B.
Engelen, H. D. Lutz, J. Mol. Struct. 2009, 919, 164–169.
[10] a) M. Mehring, M. Schürmann, R. Ludwig, Chem. Eur. J.
2003, 9, 838–849; b) T. J. R. Weakley, Acta Crystallogr., Sect.
B: Struct. Crystallogr. Cryst. Chem. 1976, 32, 2889–2890; c)
A. H. Mahmoudkhani, V. Langer, J. Mol. Struct. 2002, 609,
97–108.
[11] P. Coppens in Crystallographic Computing Copenhagen (Eds.:
F. R Ahmed, S. R. Hall, C. P. Huber), Munksgaard, 1970, pp.
255–270.
[6] S. Shimada, J. Maruyama, Y.-K. Choe, T. Yamashita, Chem.
Commun. 2009, 6168–6170.
[12] A. Altomare, G. Cascarone, C. Giacovazzo, A. Guagliardi,
M. C. Burla, G. Polidori, M. J. Camalli, Appl. Crystallogr.
1994, 27, 1045.
[13] G. M. Sheldrick, SHELXL-97, A Program for Crystal Struc-
ture Refinement, University of Göttingen, Germany 1997.
Received: December 10, 2009
[7] L. Dostál, R. Jambor, A. Ru˚zicˇka, M. Erben, R. Jirásko, Z.
ˇ
ˇ
Cernosˇková, J. Holecˇek, Organometallics 2009, 28, 2633–2636.
[8] A. Fridrichová, T. Svoboda, R. Jambor, Z. Padeˇlková, A. Ru˚z-
ˇ
icˇka, M. Erben, R. Jirásko, L. Dostál, Organometallics 2009,
28, 5522–5528.
Published Online: March 1, 2010
Eur. J. Inorg. Chem. 2010, 1663–1669
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1669