1242 NOTES
lnorgnnic Chemistry
(s), 1465 (s), 1450 (m), 1248 (m), 1185 (w),1160 (m), 1148 (sh), 1100 (m), 1031 (m), 984 (m), 930 (m), 885 (m), 730 (m), 695 (s), 617 (s), and ( m ) 560 em-'. T h e ultraviolet spectrum of t h e complex in hexane shows a maximum a t 230 nip ( e 33,000) ancl a shoulder at 285 mw ( E 12,500). T h e nmr spectrum of the complex in carbon tetrachloride, acetonitrile, and tetramethylsilane (60: 35:5) mixture shows resonances a t 7 3.00 (benzene ring, multiplet), 4.58 (H4,5, pentet), 6.32 (H3, pentet), 6.73 (He, septet), about 6.9 (H7,multiplet), and 8.77 (CHI, doublet) with respect to T M S . Relative intensities were 4 : 2 : 1 : 1 : 1 : 3.
Experimental Section T h e infrared spectra were obtained in chloroform solutions and recorded on a Perkin-Elmer Model 2 1 double-beam spectrotnetcr using sodium chloridc optics. The proton nmr spectra were recorded for approximately 15% chloroform solutions on a Varian Associates Model A-60 spectrometer using tetramethylsilane as a n internal standard. Carbon and hydrogen compositions were ascertained by combustion. Yields were calculated on the basis of the limiting reagent. Iron pentacarbonyl was purchased from Antara Chemical Co ., chromium hexacarbonyl mas purchased from Pressure ChemiAcknowledgment.-The authors wish to express cal Co., and molybdenum and tungsten hexacarbonyls were their indebtedness to the National Science Foundation gifts from Climax Molybdenum Co. T h e bicyclic phosphite for Research Grant G P 4900 which supported this work. ligands,'l8 CiH8Cr(CO)ss and CiH&10(C0)3,'~ were prepared by methods described elsewhere. A slightly greater mole ratio of ligand t o metal carbonyl or CiH,M(CO), than theoretically necessary t o yield the di- and trisubstituted products was used while a slightly smaller ratio CONTRIBUTION FROM THE CLIPPINCER LABORATORIES, was used for t h e monosubstituted complexes. The trisubstituted DEPARTMENT OF CHEMISTRY, OHIOUNIVERSITY, chromium and molybdenum complexes were prepared from the ATHENS, OHIO 45701 appropriate cycloheptatriene compound. T h e solvent used in the preparation of all trisubstituted complexes of chromium, molybdenum, and tungsten was methylcyclohexane, diethyl T r a n s i t i o n M e t a l Carbonyl Complexes ether, and toluene, respectively. Dioxane was used for Feof t h e C o n s t r a i n e d P h o s p h i t e E s t e r s : (CO&, W(C0)4L2, and W ( C 0 ) j L while the remaining complexes were prepared with n-octane. 4-Methyl-, 4-Ethyl-, a n d 4-PropylTwo general methods were used in the preparation of the com2,6,7-trioxa -1-phosphabicyclo[2.2.2]octane plexes listed in Table I . I n method A, a mixture of metal carbonyl or cycloheptatriene metal carbonyl and ligand in approxiBY WILLIAME . STASCLIFT~ ASD DAVIDG. HENDRICKER mately 30 ml of solvent was refluxed under a helium flush with magnetic stirring for the indicated time. Compounds were isoReceked December 19, 1967 lated b y suction filtration and mere washed on the filter with 12pentane, hexane, or anhydrous diethyl ether. I n some cases, The mono- and disubstituted complexes of various it was necessary to reduce the volume of t h e mixtures b y vacuum evaporation in order to obtain a filterable product. After purifimetal carbonyls with P(OCHz)&R, where R = CH3 cation was effected according t o the method listed in Table I, and C2H5, have been previously reportedj2v3and the all compounds were dried under vacuum. formation of cis-310 (CO)1(P(OCHJ3CCH3) 3 has been In method B, a mixture of metal carbonyl, ligand, and 50 ml observed in kinetic studies4 The strong 9-bonding of solvents was placed in a quartz flask. Irradiation with ultraability of the ligands2 leads one to predict that trisubviolet light (200-W Hanovia Model 654.4-10) was carried out for the time indicated under a flush of helium with magnetic stirring. stituted complexes of the type M(C0)3L3, where M = T h e mixtures were filtered by suction t o remove solid decomposiCr, ?\.lo, or W and L = phosphite esters, should be readtion products and then treated in the same manner given in ily obtainable. method A. In the preparation of some compounds, mixtures of The proton nmr spectra of the disubstituted comcarbonyl complexes of varying degrees of substitution were obpounds of the methyl and ethyl bicyclic phosphites distained. B y employing chromatography and/or fractional crystallization, it was possible t o obtain pure compounds. As a play interesting features of phosphorus spin-spin result, both isomers of two complexes could b e prepared using a c o ~ p l i n g . ~Previous '~ reports in the 1iteratu1-e~~~ sugsingle set of reaction conditions. gest that in disubstituted compounds such coupling is Preparative method rl was employed for all of t h e reactions observed only when the phosphorus ligands are in the except for the tungsten complexes and the disubstituted iron trans position. If such is the case, one would expect complex for which method B was used. Analytical data for the compounds are presented in Table 1. to observe proton absorptions having similar shapes Decomposition of the solid mono- and disubstituted complexes for compounds of the types cis-M(CO)qL2 and cisis observed after several days t o weeks upon standing in air while M(CO)aL3. The effect of the length of the alkyl chain solutions are usually stable for several hours or more. T h e on the coordination properties of ligands of the type colorless trisubstituted complexes appear t o be less stable than P(OCH2)&R may be evaluated by comparing the the disubstituted complexes.
properties of the compounds reported previously where R = CH3 and C2H5with those described herein where R = C3H7. The solubility in organic solvents of the complexes containing P(OCH2)&R ligands is enhanced by the larger C3H7 group, making their characterization in solution easier, (1) SSF College Teacher Research Participant, U'estminster College, iYew Wilrnington, Pa. (2) J. G. Verkade, R. E. McCarley, D. G. Hendricker, and I
