Synthesis and spectroscopic characterization of cyclic and polymeric phosphazenes bearing phosphine complexes

Article abstract of DOI:10.1016/S0277-5387(02)01233-0

The reactions of the cyclic phosphazenes [N₃P₃Cl₆] and [N₃P₃(O₂C₁₂ H₈)₂Cl₂] (O₂C₁₂H₈ = 2,2′-dioxybiphenyl) with

Full text of DOI:10.1016/S0277-5387(02)01233-0

Polyhedron 21 (2002) 2579Á2586
/
www.elsevier.com/locate/poly
Synthesis and spectroscopic characterization of cyclic and polymeric
phosphazenes bearing phosphine complexes
Gabino A. Carriedo a,*, Francisco J. Garc´ıa Alonso a, Pedro A. Gonza´lez a,
Carlos D´ıaz Valenzuela b,*, Nicola´s Yutronic Sa´ez b
a Departamento de Qu´ımica Orga´nica e Inorga´nica, Facultad de Qu´ımica, Universidad de Oviedo, c/ Julia´n Claver´ıa S/N, 33071 Oviedo, Spain
b Departamento de Qu´ımica, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
Received 31 May 2002; accepted 9 September 2002
Abstract
The reactions of the cyclic phosphazenes [N3P3Cl6] and [N3P3(O2C12H8)2Cl2] (O2C12H8ꢀ
diphenylphosphine phenol complex {Mn(CO)2(h5-C5H4Me)[PPh2(C6H4Ã
OH)]} (1) and Cs2CO3 in refluxing acetone gave,
respectively the phosphazeneÁphosphine complexes {N3P3[OC6H4PPh2Ã
Mn(CO)2(h5-C5H4Me)]6} (2) and {N3P3(O2C12H8)2-
[OC6H4PPh2Ã
Mn(CO)2(h5-C5H4Me)]2} (3), in good yields. The analogous reaction of the partially substituted clorophosphazene
polymer {[NP(O2C12H8)]0.6[NPCl2]0.4
in THF gave the polymeric complex [{NP(O2C12H8)}0.6{NP[OC6H4PPh2Ã
Mn(CO)2(h5-
0.5[OC4H8]n (4). Different spectroscopic data are provided for the new compounds that may be useful for the
/
2,2?-dioxybiphenyl) with the
/
/
/
/
}
/
n
C5H4Me)]2}0.4
×
/
characterization of other more complex polymeric materials.
# 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Cyclophosphazenes; Polyphosphazenes; Phenolic phosphine; Macromolecular complexes; Carbonyls; Spectroscopic characterization
1. Introduction
metal complex having a labile ligand. However, apart
from the synthetic difficulties in the preparation of the
polymeric ligand itself, this approach implies two main
complications, namely: (a) incomplete coordination of
MLn fragment to the available L groups, frequently for
steric reasons; and (b) crosslinking reactions by a double
substitution on the precursor complex by two ligands
coming from different polymeric chains [8]. In an earlier
paper [8], we reported a new direct route to W(CO)5
complexes supported in phosphazenes based on the
Transition-metal polymeric complexes deserve a great
scientific interest for many reasons, including their
potential technological importance [1], relevance to
catalysis [2,3] and other applications [4]. One special
class of metal-containing polymers are those that consist
on a polymeric main chain having pendant complexes -
Â
/
Â
/
-LÃ/MLn attached to it through a spacer. Although
several polymeric complexes of this type are known
where the main chain is a linear polyphosphazene, i.e.
reaction of the phenolic complex (CO)5WÃ
/
Ph2PC6H4Ã
/
OH with chlorophosphazenes, taking advance of the
effective chlorine substitution reaction promoted by the
presence of Cs2CO3 [10]. Herein we describe an exten-
sion of this method that allowed a very convenient
preparation in high yield of polyphosphazenes, cyclic
and polymeric, with pendant phosphine complexes of
Å
/
(NPR2)n [5], they still remain scarce. Among the best
characterized ones, are various transition metal phos-
phine-complexes (i.e. Lꢀ PPh2) [6Á8] and pyridine
complexes (Lꢀ C5H4N) [9]. The most common syn-
/
Ã
/
/
/
Ã
/
thetic route to these compounds involves the prepara-
tion of a polymer bearing the L group, followed by a
substitution reaction with an appropriate transition
the type OC6H4PPh2Ã
Mn(CO)2(h5-C5H4Me).
/
On the other hand, the characterization of complex
polymeric substances is far from simple, especially if the
solubility is low or in the case of the functionalization of
material surfaces. Therefore, all the spectroscopic evi-
dence obtained in well defined systems may be valuable
* Corresponding authors. Tel.: ꢁ
103446
E-mail address: gac@sauron.quimica.uniovi.es (G.A. Carriedo).
/
34-985-105009; fax: ꢁ34-985-
/
0277-5387/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved.
PII: S 0 2 7 7 - 5 3 8 7 ( 0 2 ) 0 1 2 3 3 - 0

2580
G.A. Carriedo et al. / Polyhedron 21 (2002) 2579Á2586
/
to deal with these other cases. Thus, we have tried to
provide IR and NMR spectroscopic data leading to
general observations that may be useful for the char-
acterization of other phosphazene polymers with orga-
nometallic complexes.
2.2. Preparation of PPh2(C6H4Ã
/
OH)
A mixture of p-bromophenol (12.5 g, 72.2 mmol), 2-
methoxypropene (13.8 ml, 144.5 mmol) and a drop of
POCl3 was stirred in the absence of light for 1 h. Four
drops of Et3N were added and the volatiles were
evaporated in vacuo. The resulting pale yellow oil
(very light sensitive) was dissolved in petroleum ether
(80 ml). To this solution was added dropwise and with
stirring a solution of LiBu 2.5 M (31.8 ml, 79.42 mmol)
in petroleum ether (30 ml). The stirring was continued
for 4 h to give a white precipitate that was filtered and
2. Experimental
2.1. General considerations
dried in vacuo. The resulting solid was dissolved at ꢂ
/
All the reactions were carried out under dry nitrogen.
K2CO3 and Cs2CO3 were dried at 140 8C prior to use.
The C3H6O used as solvent was predistilled from
KMnO4, and distilled twice from anhydrous CaSO4.
The MeOH was distilled from CaH2. The THF was
treated with KOH and distilled twice from Na in the
presence of benzophenone. Petroleum ether refers to
70 8C in THF (70 ml) and to the solution was added
dropwise a solution of PClPPh2 (8.4 ml, 47.04 mmol) in
THF (30 ml). The mixture was allowed to reach room
temperature (r.t.) and stirred overnight. Then, 20%
aqueous HCl (36 mL) was added and, after stirring for
3 h, the mixture was extracted with Et2O (4ꢃ
The extracts were stirred with an excess of solid
Na2CO3, washed with water (3ꢃ50 ml), dried over
/50 ml).
that fraction with boiling point in the range 60Á
/
65 8C.
/
The hexachlorocyclotriphosphazene [N3P3Cl6] (Fluka)
was purified from hot petroleum ether and dried in
vacuum. The cyclic [N3P3(O2C12H8)2Cl2] [11], and
[N3P3(O2C12H8)2(OC6H4PPh2)] [8], were prepared as
described elsewhere. The polymer [NPCl2]n was pre-
pared by heating the [N3P3Cl6] in solution as described
by Magill and coworkers [26]. The phosphine
Na2SO4, and filtered. The solvent was evaporated in
vacuo to give an orange oily residue that was dissolved
in CH2Cl2, filtered through silica-gel, concentrated by
evaporation in vacuo, and mixed with petroleum ether
to obtain two layers. This mixture was then kept into a
freezer until crystallization and then the white micro-
crystals were dried in vacuo. Yield: 6 g (46%).
[PPh2(C6H4Ã
/
OH)] was prepared as described in the
experimental part (a slight modified version of the
Anal. Found: C, 77.3; H, 5.5. Calc.: C, 77.7; H, 5.4%.
1H NMR (CDCl3): 7.4Á
/
6.7 (m.br., 14H, aromatic
rings); 5.3 (s.br., 1H, OH). 31P NMR (CDCl3): ꢂ
6.6.
13C NMR (CDCl3): 157.4 s, 136.5 {d, J (31PÃ13C)ꢀ
21.6}, 128.5 {d, 8}, 116.4 {d,
(31PÃ13C)ꢀ
(31PÃ13C)ꢀ C6H4]; 138.2 {d, J (31PÃ13C)ꢀ
8.3}, [PÃ
9.2}, 134.1 {d, J (31PÃ13C)ꢀ
19.3}, 129.1 {d, J
(31PÃ13C)ꢀ
10.6}, 129.0 [PPh2].
reported in Ref. [8]).
The IR spectra were recorded with a PerkinÁ
/
/
Elmer
/
/
FT Paragon 1000 spectrometer. NMR spectra were
recorded on Bruker AC-200, AC-300 and DPX 300
J
/
/
J
/
/
/
/
/
instruments, using CDCl3 as solvent. H and 13C{1H}
/
/
1
NMR are given in d relative to TMS. 31P{1H} NMR are
given in d relative to external 85% aqueous H3PO4.
Coupling constants are in Hz. C, H, N analyses were
/
/
2.3. Preparation of {Mn(CO)2(h5-
C5H4Me)[PPh2(C6H4ÃOH)]} (1)
performed with a PerkinÁ
The chlorine, Mn and P elemental analyses were
performed by Galbraith laboratories. GPC were mea-
/
Elmer 2400 microanalyzer.
/
To a solution of PPh2(C6H4Ã
/
OH) (1.85 g, 6.65 mmol)
30 8C was added the
sured with a PerkinÁ
/Elmer equipment with a model LC
in THF (40 ml) cooled at ꢂ
/
250 pump, a model LC 290 UV, and a model LC 30
refractive index detector. The samples were eluted with a
0.1% by weight solution of tetra-n-butylammonium
complex [Mn(THF)(CO)2(h5-C5H4Me)], obtained by
irradiating with UV light a solution of [Mn(CO)3(h5-
C5H4Me)] (1.88 g, 8.62 mmol) in THF (45 ml) at
ꢂ
30 8C until the carbonyl band at 2018 cmꢂ1 could
bromide in THF through PerkinÁ
/
Elmer PLGel (Guard,
/
5
4
3
˚
10 , 10 and 10 A) at 30 8C. Approximate molecular
weight calibration were obtained using narrow molecu-
lar weight distribution polystyrene standards. Tg values
were measured with a Mettler DSC 300 differential
scanning calorimeter equipped with a TA 1100 compu-
ter, at 10 8C minꢂ1. Thermal gravimetric analyses were
performed on a Mettler TA 4000 instrument. The
polymer samples were heated at a rate of 10 8C
minꢂ1 from ambient temperature to 800 8C under
constant flow of nitrogen.
not longer be observed (approximately 3.5 h). The
mixture was stirred at r.t. overnight and the volatiles
were removed in vacuo. The residue was chromato-
graphed in silicaÁgel eluting first with petroleum ether
/
and then with CH2Cl2. The CH2Cl2 fraction was
evaporated to give {Mn(CO)2(h5-C5H4Me)[PPh2-
(C6H4Ã/OH)]} as a brown solid. Yield: 2.2 g, 71%.
Anal. Found: C, 66.6; H, 4.6. Calc.: C, 66.7; H, 4.7%.
IR (n-CO-region): (CH2Cl2) 1926s, 1859s; (THF)
1930s, 1867s.

G.A. Carriedo et al. / Polyhedron 21 (2002) 2579Á
/
2586
2581
IR (KBr): 3509s (n-OH), 3056w (n-CH, aryl rings),
2922vw (n-CH, C5H4ÃMe), 1912vs, 1893m, 1850s,
1828vs (n-CO), 1600m, 1582m, 1560w, 1498m, 1482w,
1458vw, 1434m, 1420w (OC6H4ÃPPh2) 1399vw, 1375vw
(d-CH3, C5H4ÃMe), 1328w, 1273m, 1191w, 1174m,
1094s, 1029w, 829s, 748m, 696s (OC6H4ÃPPh2), 667m,
634w, 622m (d-MnCO), 524s.
1H NMR (CDCl3): 7.3Á
6.8 (m.br., 14H, aromatic
obtained by irradiating with UV light a solution of
[Mn(CO)3(h5-C5H4Me)] (0.11 g, 0.50 mmol) in THF (30
/
ml) at ꢂ
30 8C until the carbonyl band at 2018 cmꢂ1
/
/
could no longer be observed (approximately 1.5 h). The
mixture was allowed to reach r.t. and stirred for 6 h. The
volatiles were removed in vacuo, and the oily residue
/
/
was chromatographed in silicaÁgel eluting first with
/
/
petroleum ether and then with CH2Cl2. The CH2Cl2
fraction was evaporated to give 6 as a yellow solid.
Yield: 0.17 g, 62%.
Anal. Found: C, 63.4; H, 4.0; N, 2.7. Calc.: C, 63.5;
H, 4.1; N, 2.9%.
IR (n-CO-region): (CH2Cl2) 1928s, 1861s; (THF)
1929s, 1866s.
IR (KBr): 3058w (n-CH, aryl rings), 2961w, 2922w (n-
rings); 5.3 (s.br., 1H, OH); 4.2, 4.0 (m., 4H, C5H4); 1.9
(s, 3H, CH3). 31P NMR (CDCl3): 91.3. 13C NMR
(CDCl3): 234.0 {d, J (31PÃ
/
13C)ꢀ
40}, 135.6 {d, J (31PÃ
13C)ꢀ
9}, 129.9, 129.3br., 128.7
7.5}, 115.8 {d, J (31PÃ13C)ꢀ
9}
/
23, CO}; 157.3,
139.4 {d, J (31PÃ
11}, 133.2 {d, J (31PÃ
{d, J (31PÃ13C)ꢀ
/
13C)ꢀ
/
/
13C)ꢀ
/
/
/
/
/
/
/
(aromatic carbons); 99.7, 83.9, 82.6 (C5H4Me), 14.5
(Me).
CH, C5H4Ã
1435m, 1396w (aryl rings), 1376w (d-CH3, C5H4Ã
1273m (n-CÃOP), 1229m, 1170vs (n-PN), 1093s (n-PÃ
/
Me), 1927vs, 1859vs (n-CO), 1587m, 1478m,
/Me),
2.4. Preparation of {N3P3[OC6H4PPh2Ã
C5H4Me)]6} (2)
/
Mn(CO)2(h5-
/
/
OC), 936s,br. (d-POC), 885s, 837w, 786m, 752m (aryl
rings and d-PNP), 718w, 695m, 662m, 617sh, 608m,
590sh (aryl-rings and d-MnCO), 524m.
A mixture of [N3P3Cl6] (0.1 g, 0.29 mmol) and
OH)]} (0.84 g, 1.8
mmol) and Cs2CO3 (1.13 g, 3.47 mmol) in THF (20 ml)
[Mn(CO)2(h5-C5H4Me)[PPh2(C6H4Ã
/
1H NMR (CDCl3): 7.3Á
7.1 (m.br., 44H, aromatic
/
rings); 4.2, 4.0 (m., 8H, C5H4); 1.9 (s, 6H. CH3). 31P
NMR (CDCl3): 92.9 (s., PPh2), 25.7 [d, P(O2C12H8)] 9.7
was refluxed for 3 h. The solvent was removed in vacuo
and the residue was extracted with CH2Cl2 (5ꢃ
The solution was filtered and evaporated to dryness.
The residue was washed with MeOH (3ꢃ30 ml) to give
5 as a yellow solid. Yield: 0.72 g, 85%.
Anal. Found: C, 62.9; H, 4.4; N: 1.4. Calc.: C, 63.7;
H, 4.3; N, 1.4%.
IR (n-CO-region): (CH2Cl2) 1926s, 1859s; (THF)
1929s, 1866s.
IR (KBr): 3056w (n-CH, aryl rings), 2961w, 2922w (n-
/
20 ml).
[dd, P(OC6H4PP2)2]{M2X spin system, J (PÃ
13C NMR (CDCl3): 233.5 {d, J (31PÃ13C)ꢀ
24, CO};
152.1m, 138.9 {d, J (31PÃ13C)ꢀ
40.5}, 136.5 {d, J
(31PÃ13C)ꢀ40.5}, 135.1 (d, J (31PÃ13C)ꢀ
11.5}, 133.4
(d, J (31PÃ13C)ꢀ10.5), 130.1, 128.8 (d, J (31PÃ13C)ꢀ
9), 121.4m, (OC6H4PPh2); 148.6, 130.4, 130.3, 129.3,
126.8, 122.5 (OC12H8); 99.7, 83.8, 82.5 (C5H4Me); 14.5
(Me).
/
P)ꢀ93}.
/
/
/
/
/
/
/
/
/
/
/
/
/
/
CH, C5H4Ã
1434m (aryl rings), 1376w (d-CH3, C5H4Ã
(n-CÃOP), 1204s, 1189s, 1163vs (n-PN), 1091s (n-PÃ
OC), 953m, 940m (d-POC), 884m, 833m, 745m, 696s
(aryl rings and d-PNP), 662m, 619m, 596m (d-MnCO),
524m,br.
/
Me), 1927vs, 1859vs (n-CO), 1587m, 1483s,
2.5.2. Method b
A mixture of [N3P3(O2C12H8)2Cl2] (0.2 g, 0.35 mmol)
/Me), 1267m
/
/
and [Mn(CO)2(h5-C5H4Me)[PPh2(C6H4Ã
0.75 mmol) and Cs2CO3 (0.46 g, 1.4 mmol) in THF (25
ml) was refluxed for 2 h. The solvent was removed in
/OH)]} (0.35 g,
vacuo and the residue was extracted with CH2Cl2 (5ꢃ
/
1H NMR (CDCl3): 7.3Á
/
7.2Á
/
7.0 (m.br., 84H, aro-
matic rings); 4.1, 3.9 (m., 24H, C5H4); 1.9 (s, 18H, CH3).
20 ml). The solution was filtered and evaporated to
dryness to give 6 as a yellow solid that was washed with
31P NMR (CDCl3): 92.9 (s, PPh2); 8.0 (s, P3N3). 13C
methanol (2ꢃ/40 ml) and dried in vacuo. Yield: 0.45 g,
NMR (CDCl3): 233.4 {d, J (31PÃ
/
13C)ꢀ
40}, 135.9 {d, J (31PÃ
40}, 135.0 {d, J (31PÃ13C)ꢀ
11.5}, 133.3 {d, J
(31PÃ13C)ꢀ10.5}, 130.1, 128.8 {d, J (31PÃ13C)ꢀ
9),
121 {d, J (31PÃ13C)ꢀ
8}, (aromatic carbons); 99.6, 83.7,
82.4 (C5H4Me), 14.4 (Me).
/
24, CO}; 151.8,
90%.
Anal. Found: C, 62.9; H, 4.2; N, 2.7. Calc.: C, 63.5;
H,4.1; N, 2.9%.
138.7 {d, J (31PÃ
/
13C)ꢀ
/
/
13C)ꢀ
/
/
/
/
/
/
/
/
/
2.6. Preparation of [{NP(O2C12H8)}0.6{NP[OC6H4P-
Mn(CO)2(h5-C5H4Me]2}0.4
0.5(OC4H8)]n (4)
Ph2Ã
/
×
/
2.5. Preparation of {N3P3(O2C12H8)2[OC6H4PPh2Ã
/
A mixture of [NPCl2]n (1.0 g, 8.63 mmol), 2,2?-HOÃ
/
Mn(CO)2(h5-C5H4Me)]2} (3)
C6H4Ã
/
C6H4ÃOH (0.965 g, 5.18 mmol) and K2CO3 (2.86
/
g, 20.69 mmol) in THF (130 ml) was refluxed with
mechanical stirring for 10 h. Then, the complex
2.5.1. Method a
To a solution of [N3P3(O2C12H8)2(OC6H4PPh2)2] (2)
{[Mn(CO)2(h5-C5H4Me)][PPh2(C6H4Ã
/
OH)]} (4.85 g,
(0.2 g, 0.19 mmol) in THF (30 ml) cooled at ꢂ
/
30 8C
10.35 mmol) and Cs2CO3 (3.37 g, 10.34 mmol) were
added, and the reaction was continued for another 131
was added the complex [Mn(THF)(CO)2(h5-C5H4Me)],

2582
G.A. Carriedo et al. / Polyhedron 21 (2002) 2579Á2586
/
P(OC6H4PPh2)2]. 13C NMR (CDCl3): 234 {d,
(31PÃ13C)ꢀ
23, CO}; 153, 139, 134, 133, 130, 129, 121,
[(all broad, OC6H4ÃP(C6H5)2], 150, 126, 121 (all broad,
J
/
/
/
O2C12H8); 100.0, 83.7, 82.4 (C5H4Me); 71.3, 27.2,
(OC4H8); 14.1 (Me).
Mw (GPC): 1,100,000 (Mw/Mnꢀ
128 8C (DCpꢀ0.16
gꢂ1 Kꢂ1
(350 8C), ꢂ36% (425 8C). Residue at 800 8C: 41%.
/
4). Tg (DSC):
/
J
.
TGA: 22%
ꢂ
/
/
Chart 1.
h. The resulting mixture was poured into water (1.5 l) to
give a precipitate that was washed twice with water (1 l)
and dissolved in THF (200 ml). The solution was filtered
and concentrated until a viscous liquid was formed that
was precipitated slowly into water (1.5 l). The repreci-
pitation procedure was repeated in the same way from
THF/isopropyl alcohol, and THF/petroleum ether to
give a yellow solid that was dried in vacuo at r.t. for a
week. Yield: 3.3 g, 68%.
3. Results and discussion
Following a method previously described by us for
other phosphazene phosphine complexes [8], the hexa-
chlorocyclotriphosphazene [N3P3Cl6] was reacted with 6
equiv.
of
the
phenolic
phosphine
complex
OH)]} (1) (Chart
{Mn(CO)2(h5-C5H4Me)[PPh2(C6H4Ã
1) in acetone in the presence of Cs2CO3 to give the
/
Anal. Found: C, 62.9; H, 4.7; N, 2.6; P, 10.8; Mn, 7.5.
Calc.: C, 63.7; H, 4.6; N, 2.5; P, 9.9; Mn, 7.8. Chlorine
content: 0.03%.
hexametallic phosphazene complex {N3P3[OC6H4PPh2Ã
/
Mn(CO)2(h5-C5H4Me)]6} (2) in good yield and analyti-
cally pure (Chart 2).
IR (n-CO-region): (CH2Cl2) 1927s, 1860s; (THF)
1929s, 1866s.
This result is interesting, because it has been reported
[12] that the direct substitution reaction of the cy-
IR (KBr): 3058w (n-CH, aryl rings), 2927w, 2857w (n-
CH, PTHF), 1928vs, 1861vs(n-CO), 1588w, 1480m,br.,
clophosphazeneÁ
/
hexaphosphine {N3P3[OC6H4PPh2]6}
with the precursor [Mn(THF)(CO)2(h5-C5H5)] in THF
1435m, (aryl rings), 1376w (d-CH3, C5H4Ã
/
Me), 1263m
gives a mixture of complexes with OC6H4PPh2Ã
/
Mn(CO)2(h5-C5H5) units, and the saturation of all the
PPh2 sites required the presence of an important excess
of the organometallic manganese precursor. Thus, the
synthesis of the pure totally substituted complex analo-
gous to (2) was not reported.
(n-CÃOP), 1246m, 1198vs (n-PN), 1170m, 1095m (n-PÃ
/
/
OC), 940s,br. (d-POC), 832w, 786m, 752m (aryl rings
and d-PNP), 696m, 663m, 617m, 598m (aryl-rings and
d-MnCO), 526m.
1H NMR (CDCl3): 7.1Á
6.7 (m.br., 16H, aromatic
/
rings); 3.9, 3.7(m., 3.2H, C5H4); 3.4m, 1.6m (4H,
OC4H8); 1.8 (s, 2.4H, CH3). 31P NMR (CDCl3): 92.1
In a similar manner, the cyclic chorophosphazene
[N3P3(O2C12H8)2Cl2] where (O2C12H8ꢀ
/
2,2?-dioxybi-
(s., PPh2);
ꢂ
/
6.4 [m., P(O2C12H8];
ꢂ23.6 [m.,
/
phenyl) was reacted with (1) to give the bimetallic cyclic
Chart 2.

G.A. Carriedo et al. / Polyhedron 21 (2002) 2579Á
/
2586
2583
phosphazene complex {N3P3(O2C12H8)2[OC6H4PPh2Ã
/
that it could not be prepared by the ligand substitution
reaction from the precursor [Mn(THF)(CO)2(h5-
C5H4Me)], using the known phosphine containing
Mn(CO)2(h5-C5H4Me)]2} (3), also in good yield. We
observed that, in this case, the same complex 3 could be
also prepared by ligand replacement reaction from the
diphosphine {N3P3(O2C12H8)2[OC6H4PPh2]2} [8] and
[Mn(THF)(CO)2(h5-C5H4Me)] in THF.
polymer
[{NP(O2C12H8)}0.6{NP[OC6H4PPh2]2}0.4]n
[8,14]. Thus, even using a large excess of the organome-
tallic precursor the product isolated by this method had
only 50% of the available PPh2 ligands coordinated to
Mn(CO)2(h5-C5H4Me) fragments (as measured by 31P
NMR), and the elemental analysis showed a Mn content
of 9.6%, much larger than the expected (4.4%), indicat-
ing the presence of uncharacterized contaminating Mn
species. Considering the stability of 4, this shows that
the difficulty in completing the coordination of the PPh2
The reactions of the phenolic complex 1 with the
cyclic models could be successfully extended to the
partially substituted phosphazene copolymer {[NP(O2-
C12H8)]0.6[NPCl2]0.4}n, which is a polymeric counterpart
of the cyclic bis-spirophosphazene [N3P3(O2C12H8)2Cl2].
Thus, the reaction of this latter with 1 in THF in the
presence of Cs2CO3 gave the high molecular weight
polymeric complex [{NP(O2C12H8)}0.6{NP[OC6H4-
groups
in
the
[{NP(O2C12H8)}0.6{NP[OC6H4-
PPh2Ã
/
Mn(CO)2(h5-C5H4Me)]2}0.4
×
/
0.5(OC4H8)]n
(4)
PPh2]2}0.4 n
]
by the THF substitution of [Mn(THF)-
(CO)2(h5-C5H4Me)] is mainly due to the large steric
effects imposed to the entering Mn(CO)2(h5-C5H4Me)
fragments by those already present in the polymeric
chain.
(Scheme 1). The yield (68%) was good and much higher
than for the analogous polymer with W(CO)5 fragments
[8], and the effectiveness of the substitution reaction was
very high, as shown by the very low residual chorine
content in the isolated polymer (0.03% in weight). This
shows that the method in Scheme 1 may be of wide
application provided that the necessary phenolic com-
All the spectroscopic data (see Section 2) were in
accord with the structure proposed for the new com-
pounds and provided further useful experimental evi-
dences to characterize polymeric complexes of the
transition metals.
The IR spectra (cmꢂ1) in CH2Cl2 or THF solutions
of 1 to 4 (Section 2) showed the expected two strong
stretching carbonyl absorptions of the Mn(CO)2-
(C5H4CH3) groups at 1927, 1860. The solid state spectra
(KBr pellets) showed several helpful features. In Section
2 are quoted all the signals observed with appreciable
intensity. However, the assignments given (see the
discussion below) correspond only to those more
plex OHÃ
/
C6H4Ã
/
LÃ/MLn is stable under refluxing THF
for several hours.
The polymer 4 was very stable and could be stored in
the solid state for years unaltered. The Mw (by GPC)
was 1,100,000 (polydispersity indexꢀ4). Taking into
/
account that the weight of the chain units is 529.4, the
weight-averaged degree of polymerization is approxi-
mately 2000 units per chain, a value which is only
slightly low for that type of phosphazene random
copolymer [11]. The presence of some polytetrahydro-
furan (PTHF) in this copolymer, that is expected when
using THF as solvent in the substitution reaction from
[NPCl2]n [11,13], was detected and measured as de-
scribed below. The PTHF, that can be minimized if
necessary [13], represents approximately 6% in weight of
the isolated material and does not alter the efficacy of
the synthesis of 4.
relevant absorptions, and in the region 800Á600, where
/
various significant frequencies appear among other from
the vibrations of the aromatic rings, they have been
quoted under a general assignment.
The IR of the cyclic phosphazene models 2 and 3,
showed the presence of the organometallic fragment by
the two carbonyl absortions and also by two of the
The successful preparation of polymer 4 from
{[NP(O2C12H8)]0.6[NPCl2]0.4}n is valuable considering
expected bands of the MnÃ
/
C5H4CH3 ring [15], that were
clearly distinguished at 2922w (n-CH, CH3) and 1376vw
Scheme 1.

2584
G.A. Carriedo et al. / Polyhedron 21 (2002) 2579Á2586
/
(d-CH3), and by three conspicuous bands at 662m,
618m and 596m, that are related to d-MnCO modes
[15]. All those bands were absent in the spectra of the
uncoordinated phosphazene phosphines {N3P3[OC6H4-
PPh2]6} and {N3P3(O2C12H8)2[OC6H4PPh2]2}. How-
ever, in the region from 1600 to 680, that could be
potentially useful to study P-aryl compounds [16], the
IR spectra of 2 and 3 (Section 2) appear almost identical
to those of the corresponding free ligands. Thus, except
for the commented weak band at 1376, the only
significant difference was observed in a pair of very
the coordinated metallic fragment. This has been
repeatedly observed in cyclic and polymeric phospha-
zenes having pendant complexes with other ligands,
such as OC6H4Ã
/
CN [18], or OC5H4N [9,19,20]. This
effect is also noted in the chemical shifts of the
phosphorus atoms baring the groups OC6H4PPh2Ã
/
Mn(CO)2(h5-C5H4Me) in polymer 4, that are 1.6 ppm
lower than in the free phosphine polymer
[{NP(O2C12H8)}0.6{NP[OC6H4PPh2]2}0.4 [8].
1
The H NMR of all the Mn complexes showed the
(C5H4CH3) ring as two multiplets at 4.2 and 4.0, and a
singlet at 1.9 (CH3). In the case of the polymer 4, those
peaks appeared at slightly lower frequencies (3.9, 3.7
and 1.8 ppm). This is usually observed by comparing the
NMR signals of different groups when free and when
pendant from long spyro-phosphazene copolymeric
chains [9]. On the other hand, the relative intensities of
those signals with those of the aromatic protons (broad
signals between 7.5 and 6.7 ppm) gave a ratio of 0.62/
0.38 for the two phosphazene units in the copolymer,
very close to the idealized value given in the proposed
closed but well resolved peaks at 950Á940, because, in
/
the case of the metal complexes, the later, that is
assignable to d-POC modes [17], is much stronger
than the former. As this feature is also observed for
the analogous W(CO)5 complexes, it suggests a decrease
intensity of the band at 950 after the complexation of a
MLn fragment to the PPh2 group that could be useful to
denote it. However, although all the differences com-
mented between the spectra of the cyclic phosphazene
phosphines and its complexes were also found in the
spectra of the polymeric complex 4 and its correspond-
1
formula. The H spectra of polymer 4 also showed the
ing
PPh ] }
free
ligand
[{NP(O2C12H8)}0.6{NP[OC6H4-
940 band was too
presence of PTHF (peaks at 3.4 and 1.6) the intensity of
which corresponded to an amount of 0.5 OC4H8 units
per NP unit, representing 6.4% in weight.
2 2 0.4]n, in this case, the 950Á
/
broad to unambiguously show the coordination of a
metallic fragment.
A couple of bands at 2927w, 2857w in the IR of the
polymer 4, evidenced the presence of the PTHF, that
was expected in this synthesis [13].
The 13C NMR of the models 2 and 3 and the polymer
4, showed the two carbonyls Mn(CO)2 as a doublet at
234 ppm with a coupling constant 13CÁ31
P of 24 Hz,
/
and the (C5H4CH3) ring as four singlets at nearly 100,
84, 82 and 14 (CH3) ppm. Other peaks in the 13C NMR
spectra corresponded to the O2C12H8 rings (148.6,
130.4, 130.3, 129.3, 126.8, 122.5) [11], and to the
Finally, the broad band near 525 cmꢂ1, that is
observed in the spectra of 2, 3 and 4, may be attributed
to the aryloxyphosphazene scheleton (d-NPO modes)
[17], but similar bands are also present in the spectra of
the phosphine 1, therefore is was not assigned in Section
2.
The 31P NMR spectra was specially significant show-
ing the very large deshielding of the phosphorus of the
PPh2 coordinated to the manganese dicarbonyl frag-
ment as compared with those of the free phosphines.
Thus, in the free phenolic phosphine HOC6H4PPh2, in
the cyclic phosphazene hexaphosphine {N3P3[OC6H4-
PPh2]6}, and in the spyro-phosphazene bis-phosphine
{N3P3(O2C12H8)2[OC6H4PPh2]2}, the chemical shift is
OC6H4Ã
/
PPh3 units (in Table 1 are given the assign-
ments, that may be useful for the characterization of
similar phosphazenes with transition metal phosphine
complexes). As can be noticed, some peaks of the two
types of aromatic rings may interfere, as happens in the
polymer 4, where some assignments may be ambiguous,
specially those near the 130 ppm region. However, the
data in Table 1 clearly show that, in agreement with a
general rule noted by us [21], when the phenol
HOC6H4Ã
into NPÃ
pendant from cyclic or polymeric phosphazene units,
the chemical shift of the C1 carbon of the OC6H4Ã ring
/PPh2Mn(CO)2(C5H4CH3) is transformed
/
OC6H4ÃPPh2Mn(CO)2(C5H4CH3) groups
/
circa -6 ppm, while in their Mn(CO)2(C5H4Ã
complexes 1, 2 and 3, the value is near 93 ppm.
Consistently, the 31P NMR of the polymer 4 showed
/CH3)
/
is shifted approximately 5 ppm to lower frequencies,
that of the C4 increases by nearly the same amount, that
of C2 also increases, and that of the C3 remains almost
unaffected. On the other hand, the carbons of the
P(C6H5)2 rings shift very little upon the coordination
of a metallic fragment to the phosphorus atom,
three peaks at 92.1(PPh2), ꢂ
/
6.4 [NP(O2C12H8)] and
CH3)], and the
ꢂ
/
23.6 [P(OC6H4PPh2Mn(CO)2(C5H4Ã
/
intensity of the latter two were in accord with the ratio
of the units present in the proposed formula. By
comparing the chemical shift of the phosphorus of the
phosphazene rings in {N3P3[OC6H4PPh2]6} (8.8 ppm)
{N3P3(O2C12H8)2 [OC6H4PPh2]2} (25.8 for the
NP(O2C12H8), and 10.0 for the NP[OC6H4PPh2]2) [8],
with those in 2 (8.0) and 3 (25.7 and 9.7, respectively), it
can be noticed how they are sensitive to the presence of
although a large increase in the 13CÁ31
P coupling
/
constant (from 10 to 40 Hz) is clearly observed.
In the case of polymer 4, the spectrum was rather
broad, and the peaks at 130Á/129 corresponding to the
C6, C4 and C1 carbons of the O2C12H8 rings are hidden

G.A. Carriedo et al. / Polyhedron 21 (2002) 2579Á
/
2586
2585
Table 1
13C NMR data for the OÃC6H4ÃPPh2 groups in phosphazenes
a
a
d in ppm, J in Hz, CDCl3 as solvent.
under the intense signals of the C3 and C4 of the
P(C6H5)2 groups (see Table 1). The 13C NMR spectra of
polymer 4 also confirmed the presence of PTHF (71.3,
27.2 ppm).
Acknowledgements
We are grateful to the DGICYT (Project PB-1997-
1276), CSIC(Project 2001Cl0008), and to the FONDE-
CYT (Projects 7000672 and 1000672) for financial
support.
The thermal stability of the polymeric complex 4, as
measured by TGA at a heating rate of 10 8C minꢂ1
,
was only moderate. Surprisingly, the initial loss of weigh
below 150aC expected for the depolymerization of
PTHF (6%) and evaporation of the resulting THF,
was reduced to 1.25% between 0 and 250 8C. A first
important loss (22%) was centered at 350 8C, followed
by another one of 36% at 450 8C. At 800 8C the residue
was of the order of 41%. The loss of 350 8C is probably
due to the volatilisation of organic molecules arising
from the organometallic ligands, while the loss at higher
temperature correspond to the formation of volatiles
after the decomposition of the aryloxypolyphosphazene
units to give a crosslinked pyrolitic residue [22].
References
[1] F. Ciardelli, E. Tsuchida, D. Wohrle, Macromolecule*Metal
/
¨
Complexes, Springer, Berlin, 1996.
[2] P.E. Garrou, B.C. Gates, in: D.C. Sherrington, P. Hodge (Eds.),
Syntheses and Separations using Functional Polymers (chapter 3),
Wiley, New York, 1988, p. 123.
[3] C.U. Pittman, Jr., in: G. Wilkinson, F.G.A. Stone, E.W. Abel
(Eds.), Comprehensive Organometallic Chemistry, vol. 8 (chapter
55), Pergamon, London, 1982, p. 553.
[4] J.E. Sheats, C.E. Carraher, Jr., C.U. Pittman, Jr., M. Zeldin, B.
Currell (Eds.), Inorganic and Metal-Containing Polymeric Mate-
rials, Plenum, New York, 1990.
The DSC curve for 4, scanned from ꢂ
showed a clear heat capacity jump corresponding to a
glass transition with Tgꢀ128 8C (DCpꢀ
0.16 J gꢂ1
Kꢂ1). This Tg is higher than that of the free phosphine
polymer [{NP(O2C12H8)}0.6{NP[OC6H4PPh2]2}0.4
0.7[OC4H8]n (Mwꢀ800.000, Tgꢀ96 8C), made by the
same method [14], a difference due to the presence of
voluminous transition metal-ligand fragments in 4 [23Á
/
50 to 250 8C,
[5] H.R. Allcock, J.L. Desorcie, G.H. Riding, Polyhedron 6 (1987)
119.
/
/
[6] H.R. Allcock, I. Manners, M.N. Mang, M. Parvez, Inorg. Chem.
29 (1990) 522.
×
/
[7] R.A. Dubois, P.E. Garrou, K.D. Lavin, H.R. Allcock, Organo-
metallics 5 (1986) 460.
/
/
[8] G.A. Carriedo, F.J. Garc´ıa Alonso, P.A. Gonza´lez, P. Go´mez
Elipe, Polyhedron 18 (1999) 2853.
/
[9] G.A. Carriedo, F.J. Garc´ıa Alonso, J.L. Garc´ıa Alvarez, C. D´ıaz
Valenzuela, N. Yutronic Sa´ez, Polyhedron 21 (2002) 2587.
[10] G.A. Carriedo, F.J. Garc´ıa Alonso, P.A. Gonza´lez, Macromol.
Rapid Commun. 18 (1997) 371.
25] (for the similar phosphine polymer with higher Mw
the value is 115 8C, and for its W(CO)5 complex is
127 8C [8]).

2586
G.A. Carriedo et al. / Polyhedron 21 (2002) 2579Á2586
/
[11] G.A. Carriedo, L. Ferna´ndez-Catuxo, F.J. Garc´ıa Alonso, P.
Go´mez Elipe, P.A. Gonza´lez, Macromolecules 29 (1996)
5320.
[19] G.A. Carriedo, P. Go´mez Elipe, F.J. Garc´ıa Alonso, L. Ferna´n-
dez-Catuxo, M.R. D´ıaz, S. Garc´ıa Granda, J. Organomet. Chem.
498 (1995) 207.
[12] H.R. Allcock, K.D. Lavin, N.M. Tollefson, T.L. Evans, Orga-
nometalics. 2 (1983) 267.
[20] G.A. Carriedo, F.J. Garc´ıa Alonso, J.L. Garc´ıa, R.J. Carbajo, F.
Lo´pez Ortiz, Eur. J. Inorg. Chem. (1999) 1015.
[21] G.A. Carriedo, J.I. Fidalgo-Mart´ınez, F.J. Garc´ıa Alonso, E.
Rodicio Gonza´lez, A. Presa Soto, Eur. J. Inorg. Chem. (2002)
1502.
[13] G.A. Carriedo, F.J. Garc´ıa Alonso, P. Go´mez Elipe, P.A.
Gonza´lez, C. Marco, M.A. Go´mez, G. Ellis, J. Appl. Polym.
Sci. 77 (2000) 568.
[14] G.A. Carriedo, F.J. Garc´ıa Alonso, P.A. Gonza´lez, A. Presa,
work in preparation.
[22] H.R. Allcock, G.S. McDonnell, G.H. Riding, I. Manners, Chem.
Mater. 2 (1990) 425.
[15] D.M. Adams, A. Squire, J. Organomet. Chem. 63 (1973)
381.
[23] H.R. Allcock, J.T. Connolly, S. Sisco, S. Al-Shali, Macromole-
cules 21 (1988) 323.
[16] L.J. Bellamy, The Infrared Spectra of Complex Molecules, vol. 1,
Chapman and Hall, London, 1975, p. 358.
[24] H.R. Allcock, A.A. Dembek, E.H. Klingenberg, Macromolecules
24 (1991) 5208.
[17] G.A. Carriedo, F.J. Garc´ıa-Alonso, P.A. Gonza´lez, J.R. Mene´n-
dez, J. Raman Spectr. 29 (1998) 327.
[25] A.L. Crumbliss, D. Coobe, J. Castillo, P. Wisian-Neilson, Inorg.
Chem. 32 (1993) 6088.
[18] G.A. Carriedo, L. Ferna´ndez-Catuxo, F.J. Garc´ıa Alonso, P.
Go´mez Elipe, J. Organomet. Chem. 503 (1995) 59.
[26] A.N. Mujumdar, S.G. Young, R.L. Merker, J.H. Magill, Macro-
molecules 23 (1990) 14.