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Reactions of deprotonated ligands — VI
J. inorg, nucl.Chem.. I970, Vol. 32, pp. 3359to 3362. PergamonPress. Printedin Great Britain
REACTIONS
OF
DEPROTONATED
LIGANDS-VI
fl-AM I N O E T H Y L A M I D O ( E T H Y L E N E D I A M I N E ) P A L L A D I UM(1 I) IODIDE G E O R G E W. W A T T and R O B E R T L. H O O D D e p a r t m e n t of Chemistry, T h e University of T e x a s at Austin, Austin, T e x a s 78712
(Received 19 March 1970) A b s t r a c t - T h e reactions that occur b e t w e e n [Pd(en)(en-H)]! and nine electrophilic reactants are described and the nature of the products is interpreted on the basis of analytical and i.r. spectral data. INTRODUCTION
THE METHVLATION of singly and doubly deprotonated square planar ethylenediamine complexes of platinum(II) and palladium(ll)[1] and doubly and triply deprotonated octahedral ethylenediamine complexes of rhodium(Ill)[2] has been reported. Accordingly, it was of interest to investigate the extent to which such nucleophiles react with other species to form N - - X bonds, where X is an element other than nitrogen. /3-Aminoethylamido(ethylenediamine)palladium(II) iodide, [Pd(en)(en-H)]l, was selected for this purpose because: (l) It is easily prepared, (2) it has the interesting property of being reasonably stable in air although unstable in dry helium; hence maintenance of rigorously anhydrous oxygen-free conditions is avoided, and (3) use of a singly deprotonated complex affords the possibility of formation of bridged species of the type N - X - N . EXPERIMENTAL Except as described below, all experimental e q u i p m e n t and procedures were the same as those described previously[2]. U n l e s s otherwise indicated, reactions were carried out at 25°C. X-ray diffraction data (d,A) are given immediately following analytical data with relative intensities (1/Io) in parentheses, i.R. spectral data over the region 2 0 0 - 4 0 0 0 cm -j were obtained for all palladiumcontaining reaction products; these spectra are not reproduced here but are available elsewhere [3]. fl-Aminoethylamido(ethylenediamine)palladium(ll) iodide was prepared by the m e t h o d of Watt and L a y t o n [4]. This was studied in interaction with the following reactants. Benzoyl chloride. A b o u t 10 ml of C6H~COCI was distilled under reduced pressure into a previously evacuated reaction flask containing 0.5 g of [Pd(en)(en-H)]l and a magnetic stirring bar. During stirring for 4 days, the color of the solid changed from yellow to dark brown and the liquid a s s u m e d a pale purple color. Following filtration under reduced pressure, the solid was w a s h e d with CHCI3 until the washings were colorless and the solid was dried in vacuo over Mg(CIO02. (Found: Pd, 22-5; C, 27.3; H, 3.95. Calcd. for {Pd(en)[(en-H)COC6H.~]} CII: Pd, 21.6; C, 26.8: H, 4.06.) X-ray diffraction data: 7.76 (0.4), 6.99 (1.0), 6.30 (0.3), 4-12 (0.3), 3.46 (0.7), 2.97 (0-3). Picryl chloride. T h e reaction between 0-5 g of C6H2(NO2)~CI and 0.5 g of [Pd(en)(en-H)]l in 25 ml of a n h y d r o u s ether over 30 days was carried out essentially as described above; the color of the palladium complex c h a n g e d progressively from bright yellow to light brown to dark brown. T h e solid 1. 2. 3. 4.
G. G. R. G.
W. Watt and D. H. Carter, lnorg. Chem. 7, 2451 (1968). W. Watt and P. W. Alexander, Inorg. Chem. 7, 537 (1968). L. H o o d , Dissertation, T h e University of T e x a s at A u s t i n (1969). W. Watt and R. Layton,J.Am. chem. Soc. 82, 4465 (1960). 3359
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product was washed with ether. (Found: Pd, 17-6; C, 20.0; H, 3.72. Calcd. for {Pd(en)(en-H)CsH2(NO2)3]}CI1: Pd, 17.7; C, 20.0; H, 2.87.) X-ray diffraction data: 7.89 (0.5), 6'80 (1.0), 4.16 (0"8), 3.90 (0.8), 3.67 (0.4), 3.50 (0.3). Diphenyltin(lV) chloride. Similarly, 0.56 g of [Pd(en)(en-H)]l and 0.28 g of (CnHs)2SnCI2 in 5 ml of anhydrous ether were stirred for 6 days, whereupon the solid changed in color to light tan. The solid product was washed with ether. (Found: Pd, 20.3; C, 19.7; H, 4-18; N, 10.7. Calcd. for {Pd2(en)2[(en-H)2Sn(CrHs)z]}CI212: Pd, 20.3; C, 22.9; H, 3.82; N, 10.7.) X-ray diffraction data: 9.45 (0.6); 7.93 (0.7), 4-77 (0-4), 4.13 (1.0), 3.89 (0.4), 3-66 (0.4). Triphenylantimony(V) chloride. About 0'5 g of (CrHs)3SbCI2 was heated to its melting point under reduced pressure to remove traces of water and hydrogen chloride. The residue was dissolved in 10 ml of anhydrous ether and stirred with 0-3 g of [Pd(en)(en-H)]l for 5 days during which the color of the solid became pale yellow. The solid product was washed with ether. (Found: Pd, 18.9; C, 25.1; H, 4.29; N, 9.93. Calcd. for {Pd2(en)2[(en-H)~Sb(CrHs)z]}Cl212: Pd, 18.9; C, 27-7; H, 3.99; N, 9.95.) X-ray diffraction data: 9-16 (1 "0), 7.96 (0.5), 4-56 (0"2), 4.36 (0.2), 4.13 (0"3), 3.63 (0.5). Phosphorus oxychloride. Ca. 0.5 g of [Pd(en)(en-H)]l and 4 ml of POCI3 were stirred for 24 hr, whereupon the color of the solid changed to dark brown; it was washed with ether. (Found: Pd, 26.0; C, 11.3; H, 4.27. Calcd. for {Pdz(en)z[(en-H)zPO]}Clzlz: Pd, 26-3; C, 11-9; H, 3.71.) X-ray diffraction data: 7.79 (1.0), 6.21 (0.8), 3.95 (0-1), 3.63 (0.4), 3.46 (0-4), 2-97 (0-2). Sulfuryl chloride. About 10 ml of SO2C1~ and 0.5 g of [Pd(en)(en-H)]l were stirred for 48 hr during which the color of the solid changed from yellow to orange to red-brown. The solid product was washed with CC14. (Found: Pd, 22-0; C, 10.0; H, 3.65. Calcd. for {Pd(en)[(en-H)SOzCl]}Cll: Pd, 21.8; C, 9.85; H, 3.08.) X-ray diffraction data: 10.16 (0.5), 6.78 (0.3), 5.86 (1.0), 3.83 (0.2), 3.09 (0.3), 2.50 (0-2). Mercury(ll) chloride. A 0.7 g sample of [Pd(en)(en-H)]l and 0.27 g of HgCI2 (2:1 mole ratio) in 20 ml of anhydrous ether were stirred for 5 days. The intensity of color of the complex decreased; the solid product was washed with ether. (Found: Pd, 22.3; C, 10.3; H, 3.45. Calcd. for {Pd2(en),[(en-H)2Hg]}C121~: Pd, 21.8; C, 9.82; H, 3.07.) This product failed to give a satisfactory X-ray diffraction pattern. In a related experiment, 0"5 g of [Pd(en)(en-H)]l was dissolved in 200 ml of methanol by heating on a steam bath with stirring. The yellow solution was filtered and added to a solution of 0.4 g of HgCI2 in the minimum quantity of methanol. The light yellow precipitate that formed immediately was digested for 20 min on the steam bath, filtered, and dried in vacuo over Mg(C104)2 for 4 hr. (Found: Pd, 17.1; C, 7.42; H, 2.30. Calcd. for {Pd(en)[(en-H)HgC1]}Cll: Pd, 17.1; C, 7.70; H, 2.41.) This product also did not give a useful X-ray diffraction pattern. Cadmium(ll) iodide. Reactions between the deprotonated palladium complex and cadmium(ll) iodide in both 2:1 and 1:1 mole ratios were carried out as described above for the mercury(ll) case; the solid products were yellow and dark yellow, respectively. (Found: Cd, 19-8; C, 8.86; H, 2.79. Calcd. for {Pd2(en)2[(en-H)zCd]}14: Pd, 19-8; C, 8.95; H, 2.80.) X-ray diffraction data: 6.55 (0-6), 4-56 (0.1), 3.68 (1.0), 2.64 (0.3), 2.56 (0.2), 2.17 (0.4). (Found: Pd, 15.1; C, 6.67; H, 2-85. Calcd. for {Pd(en)[(en-H)Cdl]}lz: Pd, 14.8; C, 6'70; H, 2-10.) X-ray diffraction data: 6.46 (0.6), 4.50 (0.1), 3-69 (1-0), 3-24 (0.3), 2-64 (0.2), 2.17 (0-5). Aluminum(Ill) chloride. A solution of 0.2g of anhydrous A1C13 in 15 ml of ether was added to 0"5 g of [Pd(en)(en-H)]l and stirred for 5 days. The brown solid product was washed with ether. (Found: Pd, 26.5; C, 11.8; H, 4.48; C1, 8.95. Calcd. for {Pdz(en)z[(en-H)3A1]}Cl3Iz: Pd, 26-8: C, 12-1; H, 3"78; CI, 8-94.) X-ray diffraction data: 7.82 (1.0), 4.16 (0.2), 3.87 (0.2), 3.64 (0.3), 3.52 (0"3), 2.97 (0'3). Boron(Ill) fluoride. A suspension of 0.5 g of [Pd(en)(en-H)]l in 10 ml of ether was treated with BF3 over 12 hr; the color of the solid changed to dark yellow, then brown. After stirring for 3 days, the solid was isolated as described above and washed with ether. (Found: Pd, 25.0; C, 10.8; H, 3.56; N, 12.5. Calcd. for [Pd(en)2]I BF4: Pd, 24.2; C, 10.9; H, 3.64; N, 12.7.) On the assumption that the foregoint product is attributable to H F impurity in the BF3, the experiment was repeated except that the BFz was scrubbed through a saturated solution of B203 in concentrated HzSO4 [5]; the results were not substantially different. 5. H. S. Booth and K. S. Willson, Inorganic Syntheses Vol. 1. p. 21. McGraw-Hill, New York (1939).
Reactions of deprotonated ligands - V I
3361
Other reactions. Reactions between [Pd(en)(en-H)]l and CH3COCI were carried out essentially as described above for C6H5COC1. The Pd and H content of the dark red solid product were in excellent agreement with values calculated for {Pd(en)[(en-H)COCH3]}CIi, but the carbon content found was always about 5 per cent low. The i.r. spectrum did not include bands attributable to vibrations of a N-substituted amide. Reactions between [Pd(en)(en-H)]l and either excess SOC12 or SOCI~ in dry benzene led to solids that varied in color from orange to red-brown and that were of variable composition. Equally inconclusive results were obtained when H3Sii was the other reactant. There was no evidence of reaction when the deprotonated species was treated with (CH3)3SiC1 or p-NO2C6H41. DISCUSSION
The reactions described above demonstrate the electrophilic addition of nine different groups to [Pd(en)(en-H)]l; these are of two types. (1) The electrophile is generated by loss of a halide ion and adds to the single deprotonation site. (2) T w o or more halide ions are eliminated and the entering group bridges between the deprotonation sites in two or more molecules of the deprotonated complex. Although i.r. spectral data were obtained for all of the products reported here, the nature of the entering groups was such that the spectra were very complex and complete assignments could not be made. Accordingly, these spectra are not discussed here except as they bear upon the formulations given for the reaction products. The spectrum of the product of the reaction with benzoyl chloride shows clearly the presence of an N-substituted benzamide type ligand. Thus the strong Uc=o band appears at 1635 cm -J as the so-called "amide I" vibration[6.7]. The band at 1540cm -1 is assigned as the "amide I ! " band[8, 9] which has been observed in the range 1510-1570 cm -~. The relatively weak bands at 1240 and 615 cm -1 are attributable to the "amide I 1I" and "amide I V " absorptions, respectively. The product of the analogous reaction with acetyl chloride did not lead to conclusive evidence for the introduction of an acetyi group at the deprotonated site. As was true of several of the products reported here, all analyses for carbon were unacceptably low even though the other analytical data were quite satisfactory. O f more concern, however, was failure to detect Uc=o. The reaction between [Pd(en)(en-H)]I and picryl chloride should lead to an N-substituted 2,4,6-trinitroaniline coordinated to palladium. That this occurs is supported by both the analytical and infrared spectral data. The most important features of the latter are Vc-N at 1335 cm -~ and UN-H at 3340 cm-~; these and other features of the spectrum for this product are consistent with assignments made previously [7.10-13]. The formulation given above for the product of the reaction with (C6H~)2SnCI2 6. C . N . R . Rao, ChemicalApplications oflnfraredSpectroscopy. Academic Press, New York (1963). 7. L.J. Bellamy, Infrared Spectra of Complex Molecules 2nd Edn. Wiley, New York (1958). 8. R. D. B. Frazer and W. C. Price, Nature, Lond. 170, 490 (1952); idem. Proc. R. Soc. 141B, 66 (1953). 9. H. M. Randall, R. G. Fowler, N. Fuson and J. R. Dangl, Infrared Determination of Organic Structures. Van Nostrand, New York (1949). 10. N. B. Colthup,J. opt. Soc.Am.40, 397 (1950). 11. B. Franck, H. Hermann and S. Schiebe, Chem. Ber. 90, 330 (1957). 12. N. Fuson, M. L. Josien, R. N. Powell and E. Utterback,J. chem. Phys. 20, 145 (1952). 13. R. E. Richards and W. R. Burton, Trans. Faraday Soc. 45, 874 (1949).
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is supported by an absorption band at 320 c m - ' that can be reliably attributed to VSn-N on the basis of earlier work [ 14, 15]. The spectrum of this product and that of the product of the reaction with (C6Hs)3SbCIz show remarkable similarities. Thus despite very limited information from the literature concerning S b - N modes, the band at 305 c m - ' can be assigned to VSb-Nwith considerable confidence. Similarly, the establishment of a P - - N bond in the reaction with POCI~ is supported by a band at 820 c m - ' that is within the range expected [16-19] for Vp_N. If the reaction with SO2C12 results in incorporation of the -SO2C1 moiety at the deprotonation site, the i.r. spectrum of the product should include three easily recognizable features, all of which are found. Thus, Vs-o appears at 1250 to 1050 c m - ' but separate bands attributable to asymmetric and symmetric modes were not evident [10]; ~'s-N is found [20, 21] at 620 c m - ' and Vs-c, at 325 c m - ' [22]. In the light of these and earlier results [20, 21] the reasons for failure of SOC12 to react with [Pd(en)(en-H)]I in a similar manner are not evident. F o r the product of the reaction between [Pd(en)(en-H)]I and HgC12 in a 1 : 1 mole ratio, chloromercuration at the deprotonated site is confirmed by observation of VN-Hg at 540 cm-'. This assignment is made on the basis of earlier studies of the i.r. spectra of Hg(N H2)C1 and Hg(NH3)zCI2 [23-25] and other compounds containing H g - - N bonds [26]. F o r the product from the same reactants in a 2 : 1 mole ratio, assignment of vN-ng at 550 c m - ' was made on the same basis. In a reaction with the deprotonated complex in both 1 : 1 and 2 : 1 mole ratios, Cdl2 formed products apparently strictly analogous to the HgCI2 case; the spectra of the Cd and Hg complexes were closely similar. T h e secondary amine vNn appears at 3300 c m - ' in both spectra and Ucd-Nis assigned at 540 c m - ' by analogy to the corresponding mercury species. Although simple addition of the two strong Lewis acids, AICI3 and BF3, to the deprotonated site was anticipated, this did not occur in either case. The results show that the deprotonated complex reacted with AICI3 in a 3 : 1 mole ratio, the i.r. spectrum of the product showed no evidence for VAI-Cl but did include a band at 550 c m - ' that is attributable to UAI-N[27]. Despite efforts to remove H F from the BF3 employed, the results reported here can be interpreted only as involving reprotonation and addition of one BF4- anion. Acknowledgements-This work was supported by the U.S. Atomic Energy Commission and the Robert A. Welch Foundation. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
M. P. Brown, R. Okawara and E. G. Rochow, Spectrochim. A cta 16,595 (1960). R. Okawara, D. E. Webster and E. G. Rochow, J. A m. chem. Soc. 82, 3287 (1960). L. Larssen, Acta chem. scand. 6, 1470 (1952). B. Holmstedt and L. Larssen,Acta chem. scand. 5, 1179 (1951). R. B. Harvey and J. E. Meyhood, Can. J. Chem. 33, 1552(1955). D. E. C. Corbridge,J. appl. Chem. 6, 456 (1956). G. W. Watt and P. W. Alexander, lnorg. Chem. 7,537 (1968). G. W. Watt, P. W. Alexander and B. S. Manhas,J.Am. chem. Soc. 89, 6483 (1967). J. F. King and D. J. H. Smith, Can. J. Chem. 43, 1870 (I 965). S. Mizushima, !. Nakagawa and D. M. Sweeny, J. chem. Phys. 25, 1006 (1956). !. Nakagawa, R. B. Penland, S. Mizushima, T. J. Lane and J. V. Quagliano, Spectrochim. Acta 9, 199 (1957). 25. E. P. Bertin, 1. Nakagawa, S. Mizushima, T. J. Lane and J. V. Quagliano, J. Am. chem. Soc. 80, 525 (I 958). 26. K. Brodersen and H. J. Becher, Chem. Ber. 89, 1487 (1956). 27. W. Sawodny andJ. Goubeau,Z.phys. Chem. 44, 227 (1965).
REACTIONS
OF
DEPROTONATED
LIGANDS-VI
fl-AM I N O E T H Y L A M I D O ( E T H Y L E N E D I A M I N E ) P A L L A D I UM(1 I) IODIDE G E O R G E W. W A T T and R O B E R T L. H O O D D e p a r t m e n t of Chemistry, T h e University of T e x a s at Austin, Austin, T e x a s 78712
(Received 19 March 1970) A b s t r a c t - T h e reactions that occur b e t w e e n [Pd(en)(en-H)]! and nine electrophilic reactants are described and the nature of the products is interpreted on the basis of analytical and i.r. spectral data. INTRODUCTION
THE METHVLATION of singly and doubly deprotonated square planar ethylenediamine complexes of platinum(II) and palladium(ll)[1] and doubly and triply deprotonated octahedral ethylenediamine complexes of rhodium(Ill)[2] has been reported. Accordingly, it was of interest to investigate the extent to which such nucleophiles react with other species to form N - - X bonds, where X is an element other than nitrogen. /3-Aminoethylamido(ethylenediamine)palladium(II) iodide, [Pd(en)(en-H)]l, was selected for this purpose because: (l) It is easily prepared, (2) it has the interesting property of being reasonably stable in air although unstable in dry helium; hence maintenance of rigorously anhydrous oxygen-free conditions is avoided, and (3) use of a singly deprotonated complex affords the possibility of formation of bridged species of the type N - X - N . EXPERIMENTAL Except as described below, all experimental e q u i p m e n t and procedures were the same as those described previously[2]. U n l e s s otherwise indicated, reactions were carried out at 25°C. X-ray diffraction data (d,A) are given immediately following analytical data with relative intensities (1/Io) in parentheses, i.R. spectral data over the region 2 0 0 - 4 0 0 0 cm -j were obtained for all palladiumcontaining reaction products; these spectra are not reproduced here but are available elsewhere [3]. fl-Aminoethylamido(ethylenediamine)palladium(ll) iodide was prepared by the m e t h o d of Watt and L a y t o n [4]. This was studied in interaction with the following reactants. Benzoyl chloride. A b o u t 10 ml of C6H~COCI was distilled under reduced pressure into a previously evacuated reaction flask containing 0.5 g of [Pd(en)(en-H)]l and a magnetic stirring bar. During stirring for 4 days, the color of the solid changed from yellow to dark brown and the liquid a s s u m e d a pale purple color. Following filtration under reduced pressure, the solid was w a s h e d with CHCI3 until the washings were colorless and the solid was dried in vacuo over Mg(CIO02. (Found: Pd, 22-5; C, 27.3; H, 3.95. Calcd. for {Pd(en)[(en-H)COC6H.~]} CII: Pd, 21.6; C, 26.8: H, 4.06.) X-ray diffraction data: 7.76 (0.4), 6.99 (1.0), 6.30 (0.3), 4-12 (0.3), 3.46 (0.7), 2.97 (0-3). Picryl chloride. T h e reaction between 0-5 g of C6H2(NO2)~CI and 0.5 g of [Pd(en)(en-H)]l in 25 ml of a n h y d r o u s ether over 30 days was carried out essentially as described above; the color of the palladium complex c h a n g e d progressively from bright yellow to light brown to dark brown. T h e solid 1. 2. 3. 4.
G. G. R. G.
W. Watt and D. H. Carter, lnorg. Chem. 7, 2451 (1968). W. Watt and P. W. Alexander, Inorg. Chem. 7, 537 (1968). L. H o o d , Dissertation, T h e University of T e x a s at A u s t i n (1969). W. Watt and R. Layton,J.Am. chem. Soc. 82, 4465 (1960). 3359
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WATT and R. L. H O O D
product was washed with ether. (Found: Pd, 17-6; C, 20.0; H, 3.72. Calcd. for {Pd(en)(en-H)CsH2(NO2)3]}CI1: Pd, 17.7; C, 20.0; H, 2.87.) X-ray diffraction data: 7.89 (0.5), 6'80 (1.0), 4.16 (0"8), 3.90 (0.8), 3.67 (0.4), 3.50 (0.3). Diphenyltin(lV) chloride. Similarly, 0.56 g of [Pd(en)(en-H)]l and 0.28 g of (CnHs)2SnCI2 in 5 ml of anhydrous ether were stirred for 6 days, whereupon the solid changed in color to light tan. The solid product was washed with ether. (Found: Pd, 20.3; C, 19.7; H, 4-18; N, 10.7. Calcd. for {Pd2(en)2[(en-H)2Sn(CrHs)z]}CI212: Pd, 20.3; C, 22.9; H, 3.82; N, 10.7.) X-ray diffraction data: 9.45 (0.6); 7.93 (0.7), 4-77 (0-4), 4.13 (1.0), 3.89 (0.4), 3-66 (0.4). Triphenylantimony(V) chloride. About 0'5 g of (CrHs)3SbCI2 was heated to its melting point under reduced pressure to remove traces of water and hydrogen chloride. The residue was dissolved in 10 ml of anhydrous ether and stirred with 0-3 g of [Pd(en)(en-H)]l for 5 days during which the color of the solid became pale yellow. The solid product was washed with ether. (Found: Pd, 18.9; C, 25.1; H, 4.29; N, 9.93. Calcd. for {Pd2(en)2[(en-H)~Sb(CrHs)z]}Cl212: Pd, 18.9; C, 27-7; H, 3.99; N, 9.95.) X-ray diffraction data: 9-16 (1 "0), 7.96 (0.5), 4-56 (0"2), 4.36 (0.2), 4.13 (0"3), 3.63 (0.5). Phosphorus oxychloride. Ca. 0.5 g of [Pd(en)(en-H)]l and 4 ml of POCI3 were stirred for 24 hr, whereupon the color of the solid changed to dark brown; it was washed with ether. (Found: Pd, 26.0; C, 11.3; H, 4.27. Calcd. for {Pdz(en)z[(en-H)zPO]}Clzlz: Pd, 26-3; C, 11-9; H, 3.71.) X-ray diffraction data: 7.79 (1.0), 6.21 (0.8), 3.95 (0-1), 3.63 (0.4), 3.46 (0-4), 2-97 (0-2). Sulfuryl chloride. About 10 ml of SO2C1~ and 0.5 g of [Pd(en)(en-H)]l were stirred for 48 hr during which the color of the solid changed from yellow to orange to red-brown. The solid product was washed with CC14. (Found: Pd, 22-0; C, 10.0; H, 3.65. Calcd. for {Pd(en)[(en-H)SOzCl]}Cll: Pd, 21.8; C, 9.85; H, 3.08.) X-ray diffraction data: 10.16 (0.5), 6.78 (0.3), 5.86 (1.0), 3.83 (0.2), 3.09 (0.3), 2.50 (0-2). Mercury(ll) chloride. A 0.7 g sample of [Pd(en)(en-H)]l and 0.27 g of HgCI2 (2:1 mole ratio) in 20 ml of anhydrous ether were stirred for 5 days. The intensity of color of the complex decreased; the solid product was washed with ether. (Found: Pd, 22.3; C, 10.3; H, 3.45. Calcd. for {Pd2(en),[(en-H)2Hg]}C121~: Pd, 21.8; C, 9.82; H, 3.07.) This product failed to give a satisfactory X-ray diffraction pattern. In a related experiment, 0"5 g of [Pd(en)(en-H)]l was dissolved in 200 ml of methanol by heating on a steam bath with stirring. The yellow solution was filtered and added to a solution of 0.4 g of HgCI2 in the minimum quantity of methanol. The light yellow precipitate that formed immediately was digested for 20 min on the steam bath, filtered, and dried in vacuo over Mg(C104)2 for 4 hr. (Found: Pd, 17.1; C, 7.42; H, 2.30. Calcd. for {Pd(en)[(en-H)HgC1]}Cll: Pd, 17.1; C, 7.70; H, 2.41.) This product also did not give a useful X-ray diffraction pattern. Cadmium(ll) iodide. Reactions between the deprotonated palladium complex and cadmium(ll) iodide in both 2:1 and 1:1 mole ratios were carried out as described above for the mercury(ll) case; the solid products were yellow and dark yellow, respectively. (Found: Cd, 19-8; C, 8.86; H, 2.79. Calcd. for {Pd2(en)2[(en-H)zCd]}14: Pd, 19-8; C, 8.95; H, 2.80.) X-ray diffraction data: 6.55 (0-6), 4-56 (0.1), 3.68 (1.0), 2.64 (0.3), 2.56 (0.2), 2.17 (0.4). (Found: Pd, 15.1; C, 6.67; H, 2-85. Calcd. for {Pd(en)[(en-H)Cdl]}lz: Pd, 14.8; C, 6'70; H, 2-10.) X-ray diffraction data: 6.46 (0.6), 4.50 (0.1), 3-69 (1-0), 3-24 (0.3), 2-64 (0.2), 2.17 (0-5). Aluminum(Ill) chloride. A solution of 0.2g of anhydrous A1C13 in 15 ml of ether was added to 0"5 g of [Pd(en)(en-H)]l and stirred for 5 days. The brown solid product was washed with ether. (Found: Pd, 26.5; C, 11.8; H, 4.48; C1, 8.95. Calcd. for {Pdz(en)z[(en-H)3A1]}Cl3Iz: Pd, 26-8: C, 12-1; H, 3"78; CI, 8-94.) X-ray diffraction data: 7.82 (1.0), 4.16 (0.2), 3.87 (0.2), 3.64 (0.3), 3.52 (0"3), 2.97 (0'3). Boron(Ill) fluoride. A suspension of 0.5 g of [Pd(en)(en-H)]l in 10 ml of ether was treated with BF3 over 12 hr; the color of the solid changed to dark yellow, then brown. After stirring for 3 days, the solid was isolated as described above and washed with ether. (Found: Pd, 25.0; C, 10.8; H, 3.56; N, 12.5. Calcd. for [Pd(en)2]I BF4: Pd, 24.2; C, 10.9; H, 3.64; N, 12.7.) On the assumption that the foregoint product is attributable to H F impurity in the BF3, the experiment was repeated except that the BFz was scrubbed through a saturated solution of B203 in concentrated HzSO4 [5]; the results were not substantially different. 5. H. S. Booth and K. S. Willson, Inorganic Syntheses Vol. 1. p. 21. McGraw-Hill, New York (1939).
Reactions of deprotonated ligands - V I
3361
Other reactions. Reactions between [Pd(en)(en-H)]l and CH3COCI were carried out essentially as described above for C6H5COC1. The Pd and H content of the dark red solid product were in excellent agreement with values calculated for {Pd(en)[(en-H)COCH3]}CIi, but the carbon content found was always about 5 per cent low. The i.r. spectrum did not include bands attributable to vibrations of a N-substituted amide. Reactions between [Pd(en)(en-H)]l and either excess SOC12 or SOCI~ in dry benzene led to solids that varied in color from orange to red-brown and that were of variable composition. Equally inconclusive results were obtained when H3Sii was the other reactant. There was no evidence of reaction when the deprotonated species was treated with (CH3)3SiC1 or p-NO2C6H41. DISCUSSION
The reactions described above demonstrate the electrophilic addition of nine different groups to [Pd(en)(en-H)]l; these are of two types. (1) The electrophile is generated by loss of a halide ion and adds to the single deprotonation site. (2) T w o or more halide ions are eliminated and the entering group bridges between the deprotonation sites in two or more molecules of the deprotonated complex. Although i.r. spectral data were obtained for all of the products reported here, the nature of the entering groups was such that the spectra were very complex and complete assignments could not be made. Accordingly, these spectra are not discussed here except as they bear upon the formulations given for the reaction products. The spectrum of the product of the reaction with benzoyl chloride shows clearly the presence of an N-substituted benzamide type ligand. Thus the strong Uc=o band appears at 1635 cm -J as the so-called "amide I" vibration[6.7]. The band at 1540cm -1 is assigned as the "amide I ! " band[8, 9] which has been observed in the range 1510-1570 cm -~. The relatively weak bands at 1240 and 615 cm -1 are attributable to the "amide I 1I" and "amide I V " absorptions, respectively. The product of the analogous reaction with acetyl chloride did not lead to conclusive evidence for the introduction of an acetyi group at the deprotonated site. As was true of several of the products reported here, all analyses for carbon were unacceptably low even though the other analytical data were quite satisfactory. O f more concern, however, was failure to detect Uc=o. The reaction between [Pd(en)(en-H)]I and picryl chloride should lead to an N-substituted 2,4,6-trinitroaniline coordinated to palladium. That this occurs is supported by both the analytical and infrared spectral data. The most important features of the latter are Vc-N at 1335 cm -~ and UN-H at 3340 cm-~; these and other features of the spectrum for this product are consistent with assignments made previously [7.10-13]. The formulation given above for the product of the reaction with (C6H~)2SnCI2 6. C . N . R . Rao, ChemicalApplications oflnfraredSpectroscopy. Academic Press, New York (1963). 7. L.J. Bellamy, Infrared Spectra of Complex Molecules 2nd Edn. Wiley, New York (1958). 8. R. D. B. Frazer and W. C. Price, Nature, Lond. 170, 490 (1952); idem. Proc. R. Soc. 141B, 66 (1953). 9. H. M. Randall, R. G. Fowler, N. Fuson and J. R. Dangl, Infrared Determination of Organic Structures. Van Nostrand, New York (1949). 10. N. B. Colthup,J. opt. Soc.Am.40, 397 (1950). 11. B. Franck, H. Hermann and S. Schiebe, Chem. Ber. 90, 330 (1957). 12. N. Fuson, M. L. Josien, R. N. Powell and E. Utterback,J. chem. Phys. 20, 145 (1952). 13. R. E. Richards and W. R. Burton, Trans. Faraday Soc. 45, 874 (1949).
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WATT and R. L. H O O D
is supported by an absorption band at 320 c m - ' that can be reliably attributed to VSn-N on the basis of earlier work [ 14, 15]. The spectrum of this product and that of the product of the reaction with (C6Hs)3SbCIz show remarkable similarities. Thus despite very limited information from the literature concerning S b - N modes, the band at 305 c m - ' can be assigned to VSb-Nwith considerable confidence. Similarly, the establishment of a P - - N bond in the reaction with POCI~ is supported by a band at 820 c m - ' that is within the range expected [16-19] for Vp_N. If the reaction with SO2C12 results in incorporation of the -SO2C1 moiety at the deprotonation site, the i.r. spectrum of the product should include three easily recognizable features, all of which are found. Thus, Vs-o appears at 1250 to 1050 c m - ' but separate bands attributable to asymmetric and symmetric modes were not evident [10]; ~'s-N is found [20, 21] at 620 c m - ' and Vs-c, at 325 c m - ' [22]. In the light of these and earlier results [20, 21] the reasons for failure of SOC12 to react with [Pd(en)(en-H)]I in a similar manner are not evident. F o r the product of the reaction between [Pd(en)(en-H)]I and HgC12 in a 1 : 1 mole ratio, chloromercuration at the deprotonated site is confirmed by observation of VN-Hg at 540 cm-'. This assignment is made on the basis of earlier studies of the i.r. spectra of Hg(N H2)C1 and Hg(NH3)zCI2 [23-25] and other compounds containing H g - - N bonds [26]. F o r the product from the same reactants in a 2 : 1 mole ratio, assignment of vN-ng at 550 c m - ' was made on the same basis. In a reaction with the deprotonated complex in both 1 : 1 and 2 : 1 mole ratios, Cdl2 formed products apparently strictly analogous to the HgCI2 case; the spectra of the Cd and Hg complexes were closely similar. T h e secondary amine vNn appears at 3300 c m - ' in both spectra and Ucd-Nis assigned at 540 c m - ' by analogy to the corresponding mercury species. Although simple addition of the two strong Lewis acids, AICI3 and BF3, to the deprotonated site was anticipated, this did not occur in either case. The results show that the deprotonated complex reacted with AICI3 in a 3 : 1 mole ratio, the i.r. spectrum of the product showed no evidence for VAI-Cl but did include a band at 550 c m - ' that is attributable to UAI-N[27]. Despite efforts to remove H F from the BF3 employed, the results reported here can be interpreted only as involving reprotonation and addition of one BF4- anion. Acknowledgements-This work was supported by the U.S. Atomic Energy Commission and the Robert A. Welch Foundation. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
M. P. Brown, R. Okawara and E. G. Rochow, Spectrochim. A cta 16,595 (1960). R. Okawara, D. E. Webster and E. G. Rochow, J. A m. chem. Soc. 82, 3287 (1960). L. Larssen, Acta chem. scand. 6, 1470 (1952). B. Holmstedt and L. Larssen,Acta chem. scand. 5, 1179 (1951). R. B. Harvey and J. E. Meyhood, Can. J. Chem. 33, 1552(1955). D. E. C. Corbridge,J. appl. Chem. 6, 456 (1956). G. W. Watt and P. W. Alexander, lnorg. Chem. 7,537 (1968). G. W. Watt, P. W. Alexander and B. S. Manhas,J.Am. chem. Soc. 89, 6483 (1967). J. F. King and D. J. H. Smith, Can. J. Chem. 43, 1870 (I 965). S. Mizushima, !. Nakagawa and D. M. Sweeny, J. chem. Phys. 25, 1006 (1956). !. Nakagawa, R. B. Penland, S. Mizushima, T. J. Lane and J. V. Quagliano, Spectrochim. Acta 9, 199 (1957). 25. E. P. Bertin, 1. Nakagawa, S. Mizushima, T. J. Lane and J. V. Quagliano, J. Am. chem. Soc. 80, 525 (I 958). 26. K. Brodersen and H. J. Becher, Chem. Ber. 89, 1487 (1956). 27. W. Sawodny andJ. Goubeau,Z.phys. Chem. 44, 227 (1965).