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(Diethyl methylene diphosphonato) (diethyl hydrogen methylene diphosphonato)-vanadium (III)
INORG.
NUCL.
CHEM.
LETTERS
Vol. 8, pp. 225-229, 1972.
Pergamon Press.
Printed
in
Great
Britain.
(DIETHYL METHYLENE DIPHOSPHONATO) (DIETHYL HYDROGEN METHYLENE DIPHOSPHONATO)-VANADIUM (III) Chester M. Mikulski, Nicholas M. Karayannis*, Louis L. Pytlewski, Robert O. Hutchins and Bruce E. Maryanoff Department of Chemistry, Drexel University, Philadelphia, Pa. 19104 ( R e c e i v e d 2 2 November1972)
Tetraalkyl methylene diphosphonates act as chelating agents, forming adducts with various metal salts (1-3).
Metallic derivatives of the type
M+[CH{(PO)(OR)2}2 ]- have also been reported (4,5).
Dialkyl methylene diphos-
phonic acids have been utilized as extractants of metal ions from solutions (6-9).
A number of metal complexes of the latter ligands were isolated
either during the course of the extraction process or by direct synthesis (from the diprotonated ligand and a suitable metal salt)
(7-10).
The
complexes obtained by these procedures were of various types, i.e. (L = CH2[O(O)P(OR)]2):
H2[GeL3] , GEL2(7) , H[NbOL2] and H[Nb304L4] or
H5[Nb306L4] , H[TaO2L](8) ; ML 2 and MX2L or M(SO4)L (M=Zr,Hf; X=C~O 4 , C~-)(9); ML2(M=Th,U,Ce) , Fe2L3, COL(10).
The above compounds generally consist of
polynuclear neutral or anionic metal complexes (7-10).
We have recently
reported synthetic and characterization studies of polynuclear (alkoxy alkylphosphonato)- and (dialkoxyphosphato)- metal complexes, obtained by reaction of the corresponding neutral phosphoryl esters and metal halides, at elevated temperatures
(ii).
We report herewith the synthesis and char-
acterization of the complex formed by reaction of VC% 3 with tetraethyl methylene diphosphonate (TEMDP) at temperatures above 120°C:
VC~ 3 was suspended in TEMDP
(prepared by the method of Schwarzenbach and Zurc (12)) and the mixture was heated to 120°C or higher (VC£ 3 dissolves in TEMDP at 50°C).
* Amoco Chemicals Corporation, Naperville, 225
Illinois.
Immediate precip-
226
TETRAALKYL METHYLENE DIPHOSPHONATES
Vol. 8, No. 3
itation of a light green complex, accompanied by evolution of a mixture of C2H5C£, CH2=CH 2 and HC£ (cf. ref ll), occurred at these temperatures.
The new
complex, which is insoluble in all common organic solvents, water and TEMDP, was filtered, washed with acetone and ether, and dried in an evacuated desiccator over CaC£ 2.
Analytical data (A.
Bernhardt Mikroanalytisches
Labora-
torium, Elbach, W. Germany) are in agreement with theoretical values for VCIoH25P4OI2 , i.e.:
%Found (Ca£c.):
C 22.70(23.45),
H 4.91(4.92),
P 24.58
(23.80), V 9.87(9.95), C% O. The new complex was characterized by means of spectral and magnetic studies (spectra and magnetic measurements were obtained by previously described methods (ll)).
The IR spectrum (Nujol mull) of the new complex (band assignments, based
on refs. (8,9,11-15), are shown in parentheses) maxima:
2730s,sh(~cH2(o),S),
(6CH2(0))' 1360sh(6cH3'S)' l156vS(VPOO,as),
1299sh(~cH2(0))'
1090vS(VPoo,S),
aS~0cH2) , 794s,sh(YoH), region:
2450m(~OH),
2330S(~oH),
1710sh, 1660m(~OH) , 1486m
1240s'sh(~oH)'
1218vs'sh(~p=o)
1032ws(V2POCC) , 967s(~3POOC) , 826s,b(~pcp,
723m(~pcp,S);
552s(metal-ligand
shows the following absorption
tentative assignments in the low frequency
+ YOH + ~ligand )' 520s'sh(~ligand)'
440m,b,312m(both metal-ligand).
4@8m'sh(6p=o)'
Coordinated water bands are absent.
As demonstrated by the above assignments, coordinated bidentate -POO(O,O-bonded)
the new complex involves
groups (ii), as well as uncoordinated
P=O groups (16) (Vp=oOCCUrS at 1220-1210 cm -I in dialkyl methylene diphosphonic acids (8,9)).
On the other hand, bands attributable to vibrational modes of
the OH group are clearly present in the spectrum of the complex (8,14,15). H[NbOL 2] (vide supra) and analogous complexes are characterized by IR spectra devoid of -OH bands (8).
It appears,
therefore,
that the new complex is neutral,
of the type V(L)(LH)(L = CH2[O(O)P(OC2Hs)]2 ), rather than anionic (H[VL2]). The electronic spectrum of the complex is consistent with a hexacoordinated configuration for V3+:
%max,nm (band assignments given for pure Oh syrmnetry,
Vol. 8, No. 3
T E T R A A L K Y L METHYLENE DIPHOSPHONATES
although the complex is most probably distorted octahedral(ll): absorption), 3T2g(F)).
227
< 300vs(ligand
353s(3Tlg(F) -~ 3A2g?), 423s(3T1g(F) -~ 3TIg(P)) , 671s(3Tlg(F ) -~
This spectrum is quite similar to those of tris- (alkoxy alky iphos-
phonato)- V (III) complexes;
the latter compounds do not exhibit any maximum
between 300 and 400 nm, however
(ii).
The band at 353 nm is possibly due to
the 3TIg(F) + 3A2g transition, which, although rarely observed (17), has been identified at 378 nm in the solid spectrum of tris-(diethyldithiophosphato)V (III)(18).
The magnetic moment of the new complex (2.38 BM at 298°K) is
subnormal for V 3+, as is also the case with polynuclear tris-(alkoxy alkylphosphonato) or-(dialkoxyphosphato)
V (III) complexes
(ii).
The overall evidence presented above is in favor of a polynuclear, hexacoordinated structure of the type [V(L)(LH)]n (7-11). chemical formula is shown below.
A possible stereo-
This formula most probably involves exclusively
bridging -0-P-0- groups (11,19) and monodentate PO- groups; L and LH act as tridentate ligands, while each V 3+ ion is coordinated to O-atoms of four neighboring L and LH molecules
(two of each kind), which are shared by neighbor-
ing V 3+ ions.
0
0
O
_l/ V I ~0
V
/
0
228
T E T R A A L K Y L METHYLENE DIPHOSPHONATES
Vol. 8, No. 3
(only the -O and -OH groups of the ligands are shown, for simplification).
The
above structure is, of course, one of many possible, and should be considered as speculative at this point.
Extensive studies of the reaction products
between TEMDP and a variety of metal halides have been recently initiated at this laboratory, in an attempt to completely characterize these compounds. The formation of [V(L)(LH)] n under our experimental conditions, instead of [V2L3]n, as might have been anticipated (Fe2L 3 is formed by reaction of dialkyl methylene diphosphonic acids with Fe 3+ compounds
(i0)), is obviously
due to the nature of the adduct initially formed during the reaction.
In fact,
FeCI 3 and diisopropyl methylene diphosphonate reportedly form an adduct of the type FeCl3.L(formulated as [FeCI2L2][FeCI4]) [VC~(TEMDP~]+is
(i).
If initial formation of
assumed the reaction at elevated temperatures proceeds via
intermolecular interactions,
leading to the elimination of ethyl chloride,
which is partially decomposed to ethylene and HC~ (11,20).
The protonation
of one diethyl methylenephosphonato group is presumably due to the presence of HC~ in the reaction mixture
(21).
REFERENCES i.
J.A.
Walmsley and S. Y. Tyree, Inorg. Chem., 2, 312 (1963).
2.
T. H. Siddall, III, and C. A. Prohaska,
3.
W. H. Stewart and T. H. Siddall, III, J. Inorg. Nucl. Chem., 30, 1513 (1968)
4.
J . D . Baldeschwieler, F. A. Cotton, B. D. N. Rao and R. A. Schunn, J. Am. Chem. Soc., 84, 4454 (1962).
5.
O. T. Quimby~ J. D. Curry, D. A. Nicholson, J. B. Prentice and C. H. Roy, J. Organometal. Chem., 13, 199 (1968).
6.
H. Gormcan and D. Grdenid, Proc. Chem. Soc., 288 (1960); Anal. Chem., 36, 330 (1964); ~. Gorzcan'V an~ C. Djordjevi~, Croat. Chem. Acta. __37, 265 (1965); C. Djordjevic and H. Gorican, J. Inorg. Nucl. Chem., 28, 1451 (1966).
7.
D. Grdenid and V. Jagodi6$ J. Inorg. Nucl. Chem., 26, 167 (1964).
8.
C. Djordjevic, H. Gorlcan and S. L. Tan, J. Inorg. Nucl. Chem., 29, 1505 (1967).
9.
H. Meider-Gorican, J. Inorg. Nucl. Chem., 33, 1919 (]971).
Inorg. Chem., ~, 783 (1965).
.v
V
Vol. 8, No. 3
T E T R A A L K Y L METHYLENE DIPHOSPHONATES
229
V
i0.
H. Gorican and D. Grdni6, J. Chem. Soc., 513 (1964).
ii,
C. M. Mikulski, N. M. Karayannis, M. J. Strocko, L° L. Pytlewski and M. M. Labes, Inorg. Chem., 9, 2053 (1970); N. M. Karayannis, C. M. Mikulski, M. J. Strocko, L. L. Pytlewski and M. M. Labes, Inorg. Chim. Acta, ~, 455 (1970); and references therein.
12.
G. Schwarzenbach and J. Zurc, Mh. Chem., 81, 202 (1950).
13.
K. Moedritzer and R. R. Irani, J. Inorg. Nucl. Chem., 22, 297 (1961).
14.
E. Steger and K. Rehak, Z. anorg, allg. Chem., 336, 156 (1965).
15.
B. Dupuy and C. Garrigou-Lagrange, J. Chim. Phys. Physico-Chim. Biol., 65, 632 (1968); D. F. Peppard, J. R. Ferraro and G. W. Mason, J. Inorg. Nucl. Chem., 12, 60 (1958).
16.
J. J. Pitts, M. A. Robinson and S. I. Trotz, J. Inorg. Nucl. Chem., 31, 1685 (1969).
17.
D. S. McClure, J. Chem. Phys., 36, 2757 (1962).
18.
C. Furlani, A. A. G. Tomlinson, P. Porta and A. Sgamellotti, J. Chem. Soc., (A), 2929 (1970).
19.
B. P. Block, Inorg. Macromol. Rev., ~, 115 (1970); V. Giancotti and A. Ripamonti, J. Chem. Soc., (A), 706 (1969); and references therein.
20.
V. Gutmann and G. Beer, Inorg. Chim. Acta, ~, 87 (1969).
21.
C. St~izer and A. Simon, Chem. Ber., 96, 288 (1963); R. F. Hudson and D. C. Harper, J. Chem. Soc., 1356 (1958); N. M. Karayannis, C. M. Mikulski, M. J. Strocko, L. L. Pytlewski and M. M. Labes, Inorg. Chim. Acta, ~, 357 (1971).
v
NUCL.
CHEM.
LETTERS
Vol. 8, pp. 225-229, 1972.
Pergamon Press.
Printed
in
Great
Britain.
(DIETHYL METHYLENE DIPHOSPHONATO) (DIETHYL HYDROGEN METHYLENE DIPHOSPHONATO)-VANADIUM (III) Chester M. Mikulski, Nicholas M. Karayannis*, Louis L. Pytlewski, Robert O. Hutchins and Bruce E. Maryanoff Department of Chemistry, Drexel University, Philadelphia, Pa. 19104 ( R e c e i v e d 2 2 November1972)
Tetraalkyl methylene diphosphonates act as chelating agents, forming adducts with various metal salts (1-3).
Metallic derivatives of the type
M+[CH{(PO)(OR)2}2 ]- have also been reported (4,5).
Dialkyl methylene diphos-
phonic acids have been utilized as extractants of metal ions from solutions (6-9).
A number of metal complexes of the latter ligands were isolated
either during the course of the extraction process or by direct synthesis (from the diprotonated ligand and a suitable metal salt)
(7-10).
The
complexes obtained by these procedures were of various types, i.e. (L = CH2[O(O)P(OR)]2):
H2[GeL3] , GEL2(7) , H[NbOL2] and H[Nb304L4] or
H5[Nb306L4] , H[TaO2L](8) ; ML 2 and MX2L or M(SO4)L (M=Zr,Hf; X=C~O 4 , C~-)(9); ML2(M=Th,U,Ce) , Fe2L3, COL(10).
The above compounds generally consist of
polynuclear neutral or anionic metal complexes (7-10).
We have recently
reported synthetic and characterization studies of polynuclear (alkoxy alkylphosphonato)- and (dialkoxyphosphato)- metal complexes, obtained by reaction of the corresponding neutral phosphoryl esters and metal halides, at elevated temperatures
(ii).
We report herewith the synthesis and char-
acterization of the complex formed by reaction of VC% 3 with tetraethyl methylene diphosphonate (TEMDP) at temperatures above 120°C:
VC~ 3 was suspended in TEMDP
(prepared by the method of Schwarzenbach and Zurc (12)) and the mixture was heated to 120°C or higher (VC£ 3 dissolves in TEMDP at 50°C).
* Amoco Chemicals Corporation, Naperville, 225
Illinois.
Immediate precip-
226
TETRAALKYL METHYLENE DIPHOSPHONATES
Vol. 8, No. 3
itation of a light green complex, accompanied by evolution of a mixture of C2H5C£, CH2=CH 2 and HC£ (cf. ref ll), occurred at these temperatures.
The new
complex, which is insoluble in all common organic solvents, water and TEMDP, was filtered, washed with acetone and ether, and dried in an evacuated desiccator over CaC£ 2.
Analytical data (A.
Bernhardt Mikroanalytisches
Labora-
torium, Elbach, W. Germany) are in agreement with theoretical values for VCIoH25P4OI2 , i.e.:
%Found (Ca£c.):
C 22.70(23.45),
H 4.91(4.92),
P 24.58
(23.80), V 9.87(9.95), C% O. The new complex was characterized by means of spectral and magnetic studies (spectra and magnetic measurements were obtained by previously described methods (ll)).
The IR spectrum (Nujol mull) of the new complex (band assignments, based
on refs. (8,9,11-15), are shown in parentheses) maxima:
2730s,sh(~cH2(o),S),
(6CH2(0))' 1360sh(6cH3'S)' l156vS(VPOO,as),
1299sh(~cH2(0))'
1090vS(VPoo,S),
aS~0cH2) , 794s,sh(YoH), region:
2450m(~OH),
2330S(~oH),
1710sh, 1660m(~OH) , 1486m
1240s'sh(~oH)'
1218vs'sh(~p=o)
1032ws(V2POCC) , 967s(~3POOC) , 826s,b(~pcp,
723m(~pcp,S);
552s(metal-ligand
shows the following absorption
tentative assignments in the low frequency
+ YOH + ~ligand )' 520s'sh(~ligand)'
440m,b,312m(both metal-ligand).
4@8m'sh(6p=o)'
Coordinated water bands are absent.
As demonstrated by the above assignments, coordinated bidentate -POO(O,O-bonded)
the new complex involves
groups (ii), as well as uncoordinated
P=O groups (16) (Vp=oOCCUrS at 1220-1210 cm -I in dialkyl methylene diphosphonic acids (8,9)).
On the other hand, bands attributable to vibrational modes of
the OH group are clearly present in the spectrum of the complex (8,14,15). H[NbOL 2] (vide supra) and analogous complexes are characterized by IR spectra devoid of -OH bands (8).
It appears,
therefore,
that the new complex is neutral,
of the type V(L)(LH)(L = CH2[O(O)P(OC2Hs)]2 ), rather than anionic (H[VL2]). The electronic spectrum of the complex is consistent with a hexacoordinated configuration for V3+:
%max,nm (band assignments given for pure Oh syrmnetry,
Vol. 8, No. 3
T E T R A A L K Y L METHYLENE DIPHOSPHONATES
although the complex is most probably distorted octahedral(ll): absorption), 3T2g(F)).
227
< 300vs(ligand
353s(3Tlg(F) -~ 3A2g?), 423s(3T1g(F) -~ 3TIg(P)) , 671s(3Tlg(F ) -~
This spectrum is quite similar to those of tris- (alkoxy alky iphos-
phonato)- V (III) complexes;
the latter compounds do not exhibit any maximum
between 300 and 400 nm, however
(ii).
The band at 353 nm is possibly due to
the 3TIg(F) + 3A2g transition, which, although rarely observed (17), has been identified at 378 nm in the solid spectrum of tris-(diethyldithiophosphato)V (III)(18).
The magnetic moment of the new complex (2.38 BM at 298°K) is
subnormal for V 3+, as is also the case with polynuclear tris-(alkoxy alkylphosphonato) or-(dialkoxyphosphato)
V (III) complexes
(ii).
The overall evidence presented above is in favor of a polynuclear, hexacoordinated structure of the type [V(L)(LH)]n (7-11). chemical formula is shown below.
A possible stereo-
This formula most probably involves exclusively
bridging -0-P-0- groups (11,19) and monodentate PO- groups; L and LH act as tridentate ligands, while each V 3+ ion is coordinated to O-atoms of four neighboring L and LH molecules
(two of each kind), which are shared by neighbor-
ing V 3+ ions.
0
0
O
_l/ V I ~0
V
/
0
228
T E T R A A L K Y L METHYLENE DIPHOSPHONATES
Vol. 8, No. 3
(only the -O and -OH groups of the ligands are shown, for simplification).
The
above structure is, of course, one of many possible, and should be considered as speculative at this point.
Extensive studies of the reaction products
between TEMDP and a variety of metal halides have been recently initiated at this laboratory, in an attempt to completely characterize these compounds. The formation of [V(L)(LH)] n under our experimental conditions, instead of [V2L3]n, as might have been anticipated (Fe2L 3 is formed by reaction of dialkyl methylene diphosphonic acids with Fe 3+ compounds
(i0)), is obviously
due to the nature of the adduct initially formed during the reaction.
In fact,
FeCI 3 and diisopropyl methylene diphosphonate reportedly form an adduct of the type FeCl3.L(formulated as [FeCI2L2][FeCI4]) [VC~(TEMDP~]+is
(i).
If initial formation of
assumed the reaction at elevated temperatures proceeds via
intermolecular interactions,
leading to the elimination of ethyl chloride,
which is partially decomposed to ethylene and HC~ (11,20).
The protonation
of one diethyl methylenephosphonato group is presumably due to the presence of HC~ in the reaction mixture
(21).
REFERENCES i.
J.A.
Walmsley and S. Y. Tyree, Inorg. Chem., 2, 312 (1963).
2.
T. H. Siddall, III, and C. A. Prohaska,
3.
W. H. Stewart and T. H. Siddall, III, J. Inorg. Nucl. Chem., 30, 1513 (1968)
4.
J . D . Baldeschwieler, F. A. Cotton, B. D. N. Rao and R. A. Schunn, J. Am. Chem. Soc., 84, 4454 (1962).
5.
O. T. Quimby~ J. D. Curry, D. A. Nicholson, J. B. Prentice and C. H. Roy, J. Organometal. Chem., 13, 199 (1968).
6.
H. Gormcan and D. Grdenid, Proc. Chem. Soc., 288 (1960); Anal. Chem., 36, 330 (1964); ~. Gorzcan'V an~ C. Djordjevi~, Croat. Chem. Acta. __37, 265 (1965); C. Djordjevic and H. Gorican, J. Inorg. Nucl. Chem., 28, 1451 (1966).
7.
D. Grdenid and V. Jagodi6$ J. Inorg. Nucl. Chem., 26, 167 (1964).
8.
C. Djordjevic, H. Gorlcan and S. L. Tan, J. Inorg. Nucl. Chem., 29, 1505 (1967).
9.
H. Meider-Gorican, J. Inorg. Nucl. Chem., 33, 1919 (]971).
Inorg. Chem., ~, 783 (1965).
.v
V
Vol. 8, No. 3
T E T R A A L K Y L METHYLENE DIPHOSPHONATES
229
V
i0.
H. Gorican and D. Grdni6, J. Chem. Soc., 513 (1964).
ii,
C. M. Mikulski, N. M. Karayannis, M. J. Strocko, L° L. Pytlewski and M. M. Labes, Inorg. Chem., 9, 2053 (1970); N. M. Karayannis, C. M. Mikulski, M. J. Strocko, L. L. Pytlewski and M. M. Labes, Inorg. Chim. Acta, ~, 455 (1970); and references therein.
12.
G. Schwarzenbach and J. Zurc, Mh. Chem., 81, 202 (1950).
13.
K. Moedritzer and R. R. Irani, J. Inorg. Nucl. Chem., 22, 297 (1961).
14.
E. Steger and K. Rehak, Z. anorg, allg. Chem., 336, 156 (1965).
15.
B. Dupuy and C. Garrigou-Lagrange, J. Chim. Phys. Physico-Chim. Biol., 65, 632 (1968); D. F. Peppard, J. R. Ferraro and G. W. Mason, J. Inorg. Nucl. Chem., 12, 60 (1958).
16.
J. J. Pitts, M. A. Robinson and S. I. Trotz, J. Inorg. Nucl. Chem., 31, 1685 (1969).
17.
D. S. McClure, J. Chem. Phys., 36, 2757 (1962).
18.
C. Furlani, A. A. G. Tomlinson, P. Porta and A. Sgamellotti, J. Chem. Soc., (A), 2929 (1970).
19.
B. P. Block, Inorg. Macromol. Rev., ~, 115 (1970); V. Giancotti and A. Ripamonti, J. Chem. Soc., (A), 706 (1969); and references therein.
20.
V. Gutmann and G. Beer, Inorg. Chim. Acta, ~, 87 (1969).
21.
C. St~izer and A. Simon, Chem. Ber., 96, 288 (1963); R. F. Hudson and D. C. Harper, J. Chem. Soc., 1356 (1958); N. M. Karayannis, C. M. Mikulski, M. J. Strocko, L. L. Pytlewski and M. M. Labes, Inorg. Chim. Acta, ~, 357 (1971).
v