Inorg. Chem. 1985, 24, 4152-4158
4152
trends are demonstrated qualitatively by t h e selection of vibrational frequencies shown in Table 11. I t is noted t h a t t h e observed
frequencies for R d R e , which occur over a narrow range,’ do not include any fully bridged molecules without axial ligands. A detailed examination of these effects should be a fruitful area for future application of molecular mechanics to t h e study of dimetal systems.
Acknowledgment. I am grateful t o Professor F. A. Cotton for t h e hospitality extended while this work was carried o u t in his laboratory and for alerting me to many of t h e problems treated here and also t o the University of the Witwatersrand for granting m e a year’s sabbatical leave. Registry No. Cr, 7440-47-3; Mo, 7439-98-7; W, 7440-33-7; Re, 7440-1 5-5.
Contribution from the Department of Chemistry, Tulane University, New Orleans, Louisiana 701 18
Synthesis of New Hybrid Phosphine Amine and Phosphine Amide Compounds. Preparation of a Series of New Phosphine Amido Chelate Complexes of Palladium(I1) and Platinum(I1) and Their Reactions with Bases and Brernsted Acids D A V I D HEDDEN and D. M A X R O U N D H I L L * Received March 15, 1985 The phosphine amine and phosphine amide compounds o-Ph2PC6H4NHCH2Ph(PNHBz), o-Ph2PC6H4CH2NHPh(PCNHPh), o-Ph,PC,H,NHC(o)Ph (PNH(CPhO)), and o-PhzPC6H4C(0)NHPh(P(C0)NHPh) have been synthesized and characterized. The reaction of P N H ( C P h 0 ) or P ( C 0 ) N H P h with PtCi2- or PdC1;- gives trans-PtCl,L2 or -PdCl,L, (L = PNH(CPh0) or P(C0)NHPh)) where L is bonded monodentately through phosphorus. Treatment of these complexes with bases can be used to synthesize the N-bonded amido complexes cis- and trans-M(P(CO)NPh), (M = Pd, Pt) and cis-Pt(PN(CPhO)),. The amido complexes react with HCI to give MCI,(PNH(CPhO)), and MCI,(P(CO)NHPh), (M = Pd, Pt). Structures are deduced by a combination of IR, ‘ H NMR, and 3’P{’HJN M R techniques.
The coordination chemistry of chelate ligands having mixed functionality types has received extensive study. An important aspect of this work is the development of hybrid ligands where one arm of t h e chelate is a tertiary phosphine t h a t will selectively coordinate t o group elements of the second- and third-row transition metals.’ These functionalized phosphines have been used as chelate ligands in complexes where it is desirable t o have a hinging chelate arm available for ready substitution.* Alternatively the concept has been used t o complex functional groups that usually only poorly coordinate3 or to assemble hybrid ligands for the synthesis of heter~bimetallics.~W i t h this intramolecular effect, “chelate-assisted oxidative addition” has been induced with
C-H,5 Si-H,6 N-H,’ and C-Cs bonds. In general, these reactions (1) The term “hybrid ligand” refers to a multidentate ligand which has both
(2)
(3)
(4) (5)
a hard and a soft donor group: Bertini, I.; Dapporta, P.; Fallani, G.; Sacconi, L. Inorg. Chem. 1971, io, 1703-1707. McAuliffe, C. A,; Levason, W. “Phosphine, Arsine and Stibine Complexes of the Transition Metals”; Elsevier: Amsterdam, 1979. Erastov, 0.A,; Nikonov, G. N. Russ. Chem. Rev. (Engl. Trawl.) 1984,53, 369-382. Braunstein, P.; Matt, D.; Dusausoy, Y.; Fischer, J.; Mitschler, A.; Ricard, L. J. Am. Chem. SOC.1981, 103, 5115-5125. For an exception see: Borowski, A. F.; Cole-Hamilton, D. J.; Wilkinson, G. N o w . J . Chim. 1978, 2, 137-144. Rauchfuss, T. B.; Roundhill, D. M. J . Am. Chem. SOC.1974, 96, 3098-3105. Rauchfuss, T.; Roundhill, D. M. J . Orgunomer. Chem. 1973, 59, C30-C32. These ligands have been termed hemilabile: Jeffrey, J. C.; Rauchfuss, T. B. Inorg. Chem. 1979, 18. 2658-2666. Rauchfuss, T. B.; Patino, F. T.; Roundhill, D. M. Inorg. Chem. 1975, 14,652-656. Empsall, H. D.; Hyde, E. M.; Pawson, D.; Shaw, B. L. J . Chem. SOC.,Dalton Trans. 1977, 1292-1298. Empsall, H. D.; Johnson, S.; Shaw, B. L. J. Chem. SOC.,Dplton Trans. 1980, 302-307. Bucknor, S. M.; Draganjac, M.; Rauchfuss, T. B.; Fultz, W. C.; Rheingold, A. L. J. Am. Chem. SOC.1984, 106, 5379-5381. Hoots, J. E.; Rauchfuss, T. B.; Schmidt, S. P.; Jeffery, J. C.; Tucker, P. A. “Catalytic Aspects of Metal Phosphine Complexes”;Alyea, E. C., Meek, D. W., Eds.; American Chemical Society: Washington, DC, 1982; Adv. Chem. Ser. No. 196, pp 303-31 1. Rauchfuss, T. B. In “Homogeneous Catalysis with Metal phosphine Complexes”; Pignolet, L. H., Ed.; Plenum Press: New York, 1983; pp 239-256. Maisonnet, A.; Farr, J. P.; Olmstead, M. M.; Hunt, C. T.; Balch, A. L. Inorg. Chem. 1982, 21, 3961-3967. Rauchfuss, T. B. J . Am. Chem. SOC.1979,101, 1045-1047. Suggs, J. W. J . Am. Chem. SOC.1978, 100, 640-641.
0020-1669/85/1324-4152$01.50/0
c a n be considered t o be analogous t o t h e well-known orthometalation reactions, where t h e close proximity between t h e ortho hydrogen and t h e transition-metal center enhances the r e a ~ t i v i t y . ~ The feasibility of effecting 0-H or N-H cleavage by these intramolecular-assisted reactions with functionalized phosphines was apparent after the synthesis of o-(diphenylphosphino)phenolIo and o-(dipheny1phosphino)aniline.I’ If w e pursue the analogy t h a t t h e ortho-metalation reaction is a good model for N-H activation, we will facilitate t h e insertion of a metal center into t h e N-H bond if the amino group h a s bulky substituents incorporated into the amide or secondary amine.12 This paper describes t h e synthesis of our new hybrid phosphine amine and phosphine amide ligands and also t h e preparation of the phosphine a m i d e complexes with platinum(I1) and palladium(I1). In addition t o t h e characterization of the amide complexes, this first paper of ours from the project describes the reaction chemistry of the amide and amido complexes with external bases and acids, t o effect t h e interconversion between complexed-amido and free-amide functionalities. T h e secondary-amide- a n d amine-functionalized tertiary phosphines described in this paper are functionalized triphenylphosphines. The syntheses take full advantage of t h e properties of triarylphosphines, which can be easily modified by known synthetic procedures. Every a t t e m p t h a s been m a d e to develop methods t h a t allow for facile modification of t h e R substituent in o-Ph2PC,H,NHR while t h e integrity of t h e remainder of t h e
(6) Auburn, M. J.; Holmes-Smith, R. D.; Stobart, S . R. J . Am. Chem. SOC. 1984, 106, 1314-1318. (7) Hedden, D.; Roundhill, D. M.; Fultz, W. C.; Rheingold, A. R. J . Am. Chem. SOC.1984, 106, 5014-5016. (8) Suggs, J. W.; Cox, S. D. J . Orgunomet. Chem. 1981, 221, 199-201. Suggs, J. W.; Jun, C.-H. J . Am. Chem. SOC.1984, 106, 3054-3056. (9) Collman, J. P.; Hegedus, L. S. “Principles and Applications of Organotransition Metal Chemistry”; University Science Books: Mill Valley, CA, 1980; p 213. ( I O ) Rauchfuss, T. B. Inorg. Chem. 1977, 16, 2966-2968. (11) Cooper, M. K.; Downes, J. M. Inorg. Chem. 1978, 17, 880-884. (12) Bottomley, A. R. H.; Crocker, C.; Shaw, B. L. J . Organomet. Chem. 1983, 250, 617-626.
0 1985 American Chemical Society
Hybrid Phosphine Amine and Amide Compounds molecule is retained. The choice of triaryl- over trialkylphosphines simply reflects our preference for using organophosphorus compounds that have the highest oxidative stability at phosphorus.
Experimental Section Physical Measurements. Melting points were determined on a Fisher-Johns apparatus and are uncorrected. IR spectra (4000-600 cm-') were recorded on a Perkin-Elmer Model 383 spectrometer as Nujol mulls. ' H N M R spectra were obtained on a Nicolet NTC-200 spectrometer at 200 MHz as CDCI, solutions using with internal Me4Si reference. "C('H] and 3'P(1H]N M R spectra were obtained at 15.03 and 24.15 MHz, respectively, on a JEOL FX60 spectrometer as CDC13 solutions. "C N M R spectra were referenced to internal Me4Si (6 = 0.00) or CDCI, (6 = 77.0). N M R spectra were referenced to 85% H3PO4 in acetone-d, by substitution. All N M R shifts are referenced as high frequency positive. Combustion analyses were performed by Galbraith Laboratories Inc. Materials. Tetrahydrofuran was dried by refluxing over purple sodium/benzophenone in a nitrogen atmosphere, a freshly distilled sample being collected immediately prior to each use. Pyridine was sequentially dried and distilled from powdered KOH and CaH2 and then stored under a nitrogen atmosphere over activated 3A molecular sieves. Benzoyl chloride was vacuum distilled and used immediately. Acid-free benzaldehyde was obtained by washing a 50-mL portion with 10" portions of 10% aqueous sodium carbonate until COz evolution ceased. The organic portion was dried over MgSO, and collected by vacuum distillation. The compounds o-(diphenylphosphino)aniline," o-(diphenyloxophosphoranyl)aniline," o-(diphenylpho~phino)benzaldehyde'~and o(diphenylphosphino) benzoic acid1, were prepared as described previously. o-Dinitrobenzene was either prepared according to the literature method or was purchased from Aldrich Chemical Co. n-Butyllithium (2.3 M) (Alfa Inorganics) was standardized by titration with 3,5-dimethoxybenzyl alcohol. All other commercially obtained reagents were used as supplied. The syntheses of phosphorus-containing compounds were carried out in deoxygenated solvents under a nitrogen atmosphere. Once isolated as pure solids, all new phosphine compounds are relatively air-stable and precautions for their storage are unnecessary. In manipulations requiring reduction of solvent volume a rotary evaporator was used. o -(Diphenyloxophosphoranyl)-N-benzylaniline ( 0 - P h 2 P (0)C6H4NHCH2Ph)(P(0)NHBz). o-(Diphenyloxophosphorany1)aniline (2.12 g, 7.3 mmol), acid-free benzaldehyde (0.77 g, 7.3 mmol), and PtC12 (50 mg) were placed in a 100" single-neck round-bottom flask containing absolute ethanol (50 mL) and a magnetic stir bar. The flask was fitted to a Brown hydrogenator and the system purged with nitrogen for 30 min. The system was activated, and the reaction continued until the theoretical volume of an aqueous solution of NaBH4 (1-2 M) had been consumed. The suspension was vacuum-filtered through Celite, and the solids were washed with absolute ethanol (4 X 25 mL). After reduction of the filtrate volume to ca 5 mL, addition of aqueous KOH (10%solution) gave a white oil. The solids were extracted with diethyl ether (4 X 25 mL), and the combined extracts were dried over MgSO,. After filtration, the solvent was removed to give a yellow oil. Unreacted benzaldehyde was removed by trap-to-trap distillation. Vacuum distillation (1 torr) of the residue gave the product as a white solid, which was collected over the temperature range 250-260 O C . Yield 1.62 g (60%). The compound can be recrystallized as needles by adding water to the cloud point of an acetone solution and cooling the solution at -10 "C for 24 h. The filtered product was dried in vacuo for 48 h at 80 OC; mp 114-1 15 OC. Anal. Calcd for C,,H,,NOP: C, 78.3; H , 5.78; N , 3.65; P, 8.08. Found: C, 78.1; H , 5.84; N , 3.54; P, 8.24. The hydrogenation step can be carried out by using a Parr hydrogenation apparatus, but significant scale up of the synthetic procedure results in decreased yield. o -(Diphenylphosphino)-N-benzylaniline(o-Ph2PC,H4NHCH2Ph) (PNHBz). o-(Diphenyloxophosphorany1)-N-benzylaniline (12.4 g, 32.3 mmol) and diphenylsilane (5.96 g, 32.3 mmol) were placed in a 100" single-neck round-bottom flask. The flask was connected to a gas buret via Tygon tubing and then placed in a sand bath at 180 O C . After evolution of the calculated quantity of hydrogen (800 mL at 298 K), a process requiring about 8 h, the flask was removed from the sand bath and the gas buret connection replaced with a connection to a nitrogen bubbler. After the reaction was cooled to ambient temperature, the white residue was extracted with deoxygenated methanol (10 X 50 mL). Methanol removal yielded a yellow oil. The yellow impurity was removed by passing the oil through a Florisil plug (4 cm X 10 cm) and eluting with toluene. Removal of the toluene followed by recrystallization of the resulting oil from a minimum volume of boiling ethanol gave the crys(13) Landvatter, E. F.; Rauchfuss, T. B. Organometallics 1982, I , 506-513. Hoots, J. E.; Rauchfuss, T. B.; Wrobleski, D. A. Inorg. Synth. 1982, 21, 175-179.
Inorganic Chemistry, Vol. 24, No. 24, 1985 4153 talline solid: yield 8.9 g (75%); mp 87-88 OC. Anal. Calcd for C2SH22NP:C, 81.7; H, 6.04; N , 3.81; P, 8.43. Found: C, 81.5; H, 6.24; N , 3.54; P, 8.27. o - ( D i p h e n y l p h o s p h i n o ) - N-phenylbenzylamine (0 Ph2PC6H4CH2NHPh)(PCNHPh). o-(Dipheny1phosphino)benzaldehyde (16.9 g, 58 mmol) and freshly distilled aniline (5.42 g, 58 mmol) were dissolved with stirring in absolute ethanol (200 mL). After 1 h, during which time some precipitate had formed, excess sodium borohydride (4 g) was added in portions. The mixture was stirred for 1 h. Filtration gave an orange solid. The solid was washed with methylene chloride (100 mL in portions), leaving a white residue. Removal of the solvent (CH2C12)gave an orange solid. Crystallization of this solid from a minimum volume of boiling ethanol gave the product as a white powder, yield 12.9 g (60%). Final purification to white crystalline needles was achieved by addition of hexane to a solution of the compound in a minimum volume of CH2CI2. The compound was dried in vacuo at 25 OC for 24 h; mp 135-137 "C. Anal. Calcd for C2SH22NP:C, 81.7; H, 6.04; N, 3.81; P, 8.43. Found: C, 81.7; H, 5.95; N , 3.73; P, 8.37. o - (Dipheny lphosphino ) - N -benzoylaniline ( 0 -Ph2PC,H4NHC(0)Ph) (PNH(CPh0)). o-(Dipheny1phosphino)aniline (2.46 g, 8.9 mmol) and dry pyridine (2.12 g, 26.7 mmol) were dissolved in dry T H F (10 mL) contained in a 25" two-neck round-bottom flask fitted with a septum, an oil bubbler connected to a nitrogen source, and a magnetic stir bar. Benzoyl chloride (1.25 g, 8.9 mmol) was rapidly added to the stirred solution via syringe. The suspension containing py.HC1 was stirred for 2 h. The precipitate was filtered and washed with dry T H F (20 mL in portions). Solvent removal left a viscous oil. The oil was washed with water (6 X 25 mL) and then dissolved in dichloromethane (1 5 mL) and the solution dried over MgS04. The filtered solution was reduced in volume to 3 mL, hexane (100 mL) was added, and the cloudy solution was stored at -10 OC. The resulting white needles were collected by filtration, lightly washed with hexane 10 mL), and dried in vacuo at 25 OC for 24 h: yield 2.81 g (83%), mp 107-108 OC. Anal. Calcd for C2,H2,NOP: C, 78.7; H, 5.29; N , 3.67; P, 8.12. Found: C, 78.8; H, 5.47; N , 3.67; P, 8.22. This procedure can be scaled up 10-fold without loss of purity or yield. o-(Dipbenylphosphino)-N-phenylbenzamide( 0 -Ph2w6H4C(0)NHPh) (P(C0)NHPh). o-(Dipheny1phosphino)benzoic acid (6.12 g, 20 mmol) and freshly distilled aniline (0.93 g, 20 mmol) were dissolved with stirring two-neck round-bottom flask in CHC13 (40 mL) contained in a 250" fitted with a 125-mL dropping funnel and a nitrogen bubbler. The dropping funnel was charged with a solution of N,N'-dicyclohexylcarbcdiimide (4.12 g, 20 mmol) in CHC13 (50 mL). The flask was placed in an ice bath and allowed to cool. The diimide was added dropwise over 30 min. The mixture was stirred for 2 h as it warmed to ambient temperature. N,N'-Dicyclohexylurea was removed by filtration, and solvent removal from the filtrate gave a yellow oil. The oil was chromatographed on silica gel (230-400 mesh, 6 cm X 40 cm column, CH2CI2eluant). The lead eluant was P ( C 0 ) N H R . Solvent removal gave P ( C 0 ) N H R (3.41 g) as a white powder in 56% yield. Final purification was by recrystallization from CHzC12/hexane. The white needles were filtered and dried in vacuo at 25 OC for 24 h; mp 179-180 OC. Anal. Calcd for C25HzoNOP: C, 78.7; H, 5.29; N , 3.67; P, 8.12. Found: C, 78.8; H, 5.34; N , 3.66; P, 8.06. Isolation by vacuum distillation (255-260 OC (1 mm)) gives the other rotational isomer. Anal. Calcd for C2,H20NOP: C, 78.7; H, 5.29; N , 3.67; P, 8.12. Found: C, 78.6; H, 5.35; N, 3.64; P, 7.99. This isolation procedure is not the one of choice for this compound if isomer selectivity is not required since thermal decomposition during the distillation results in lowered yield. t r s n ~ - P t C l ~ ( P N H ( C P h o (1). ) ) ~ K2PtCI4(400 mg, 0.96 mmol) was dissolved in H 2 0 / C H , C N (4 mL/12 mL) in a 100-mL round-bottom flask fitted with a magnetic stir bar. The flask was equilibrated to the oil bath temperature (60 "C). To the solution was added PNH(CPh0) (735 mg, 1.93 mmol) dissolved in CH3CN (20 mL) dropwise over 5 min. Stirring for 1 h caused the solution color to change from red to yellow as a yellow precipitate formed. The flask was removed from the oil bath and allowed to cool to room temperature. The filtered product was washed with water (3 X 10 mL), ethanol (3 X 10 mL), and then pentane (3 X 5 mL), followed by drying in vacuo. Yield 931 mg (94%); mp 27C-275 OC dec. Anal. Calcd for C5,H,Cl2N2O2P2Pt: C, 58.4; H, 3.92; N, 2.72; P, 6.02; CI, 6.89. Found: C, 58.5; H, 4.00; N , 2.89; P, 6.29; C1, 6.90. t r s n ~ - P t C l ~ ( P ( C 0 ) N H P(2). h ) ~ Using a procedure analogous to that for 1 with KZPtCl4(400 mg, 0.96 mmol) and P(C0)NHPh (735 mg, 1.9 mmol) gave 2 (920 mg, 93% yield) as a pale yellow powder, mp 250-253 OC dec. Anal. Calcd for C5OH,Cl2N2O2P2Pt: C, 58.4; H, 3.92; P, 6.02. Found: C, 58.6; H , 4.04; P, 5.94. cis-Pt(PN(CPhO))2 (3). Method A. Complex 1 (250 mg, 0.24 mmol) was suspended in CH3CN/Et3N (19 mL/1 mL) and the mixture
4154 Inorganic Chemistry, Vol. 24, No. 24, 1985 refluxed with stirring for 60-90 min. The reaction mixture was cooled, and the yellow-green solution was filtered. Reduction in filtrate volume to ca. 2 mL gave a pale yellow powder, which was shown by 31PN M R spectroscopy to be impure 3. Preparative-scale T L C (silica gel 60 F254, 2-mm layer thickness or 20 cm X 20 cm plates; E M Reagents, MC/B Inc.) using acetonitrile as eluant with the complexes applied to the plate as a solution in dichloromethane gave one broad band. The material was extracted with dichloromethane (2 X 100 mL) and the filtered extracts were combined and reduced in volume to 2 mL. Dropwise addition of diethyl ether (20 mL) precipitated pure 3 as yellow translucent crystals, which were filtered and dried in vacuo. Anal. Calcd for C50H3&02P2Pt: C, 62.8; H , 4.00; P, 6.48. Found: C, 62.3; H, 4.27; P, 6.38. Method B. Complex 1 (150 mg, 0.14 mmol) and excess sodium tert-butoxide (200 mg, 2.0 mmol) were suspended in dry acetonitrile (25 mL) under nitrogen. After 48 h the suspension was filtered, and the filtrate was evaporated to dryness. The yellow-green solid was recrystallized from CH2C12/Et20to give 3, yield 95 mg (68%). c~~-P~CI~(PNH(CP~O))~~O.~SCH~CI,~E~~O (4). Complex 3 (50 mg, 0.05 mmol) was dissolved in CH2CI2(2 mL). Hydrogen chloride was bubbled through the solution for 5 min, causing the color of the solution to change from yellow-green to pale yellow. Excess hydrogen chloride was removed by purging the solution with a vigorous stream of nitrogen. Dropwise addition of diethyl ether (20 mL) precipitated the product. The solids were isolated by filtration, washed with diethyl ether (10 mL), and dried in vacuo: yield 50 mg (80%); mp >300 OC. A recrystallization from dichloromethane and diethyl ether was necessary for the isolation of pure material. Anal. Calcd for C54,25H505CI25N203P2Pt: C, 58.0; H , 4.52; N , 2.49; CI, 7.88. Found: C, 58.0; H , 4.14; N , 2.56; CI, 8.79. trans-Pt(P(CO)NPh), (5). Complex 2 (100 mg, 0.097 mmol) and excess sodium methoxide (200 mg, 3.7 mmol) were suspended in dry acetonitrile (20 mL). The mixture was stirred in a dry atmosphere for 3 days. The solution was filtered, and the remaining solids were washed with dichloromethane (50 mL). The combined filtrate was evaporated to leave a yellow solid. Recrystallization from dichloromethane and hexane gave a yellow powder, which was washed with hexane and dried in vacuo; yield 85 mg (89%). Anal. Calcd for CSOH38N202P2FY: C, 62.8; H, 4.00; P, 6.48. Found: C, 61.9; H, 4.34; P, 6.22. cis-Pt(P(CO)NPh), (6). Complex 2 (100 mg, 0.097 mmol) and excess Dabco (200 mg, 18 mmol) were suspended in acetonitrile (50 mL), and the mixture was refluxed for 1 h under nitrogen. After the reaction was cooled to room temperature, the solvent was removed to give a yellow-green residue. This solid was dissolved in dichloromethane (10 mL), filtered, and extracted with aqueous NaCl (4 X 40 mL of 10% NaCI) to remove excess base. The organic layer was dried over anhydrous MgS04, reduced in volume to ca. 2 mL, and treated with diethyl ether dropwise (40 mL) to precipitate 6 as a pale yellow powder. The complex was filtered, washed with diethyl ether (10 mL), and dried in vacuo; yield 63 mg (68%). Anal. Calcd for CSOH38N202P2Pt: C, 62.8; H , 4.00. Found: C, 61.9; H, 4.51. cis-PtCI,(P(CO)NHPh), (7). Complex 6 (107 mg, 0.1 1 mmol) was dissolved in dichloromethane (5 mL) and the solution treated with HCl(g) for 5 min as the yellow-green solution changed to pale yellow. Excess HCI was removed by a nitrogen purge, and the filtered solution was reduced in volume to ca. 2 mL. Addition of diethyl ether (20 mL) gave the complex as pale yellow microcrystals, which were filtered, washed with diethyl ether, and dried in vacuo: yield 82 mg (72%); mp 217-220 OC. Anal. Calcd for C50H40C12N202P,Pt:C, 58.4; H, 3.92. Found: C, 58.3; H, 4.19. PdCI,(PNH(CPhO)), (8). Sodium tetrachloropalladate(I1) (203 mg, 0.69 mmol) was dissolved in acetonitrile (15 mL) and the solution filtered. A solution of P N H ( C P h 0 ) (526 mg, 1.38 mmol) in acetonitrile (40 mL) was then rapidly added to the stirred Na2PdClPsolution. After 15 min, the yellow precipitate was filtered and washed successively with methanol (3 X 5 mL) and diethyl ether (3 X 5 mL). The complex was dried in vacuo: yield 512 mg (79%); mp 239-241 OC. Final purification was by recrystallization from CH2CI2/MeOH. Anal. Calcd for C50H,C12N202P2Pd: C, 63.9; H, 4.29; N , 2.98. Found: C, 63.7; H, 4.31; N , 2.95. PdCI,(P(CO)NHPh), (9). Using a procedure analogous to that for 8 with Na2PdCll (400 mg, 1.35 mmol) and P ( C 0 ) N H R (1.04 g, 2.7 mmol) gave 1.15 g (90%) of the complex as a light orange powder. The complex can be recrystallized in small batches (
