Polyhedron Vol. 9, No. 24, pp. 290-2909, 1990

Printed in Great Britain

0277-5387190 53.00+.00

Pergamon Press plc

PREPARATION AND REACTIVITY OF PhP(C,Me4H)2 AND Ph2P(CSMe4H). X-RAY CRYSTAL STRUCTURES OF Mo(CO),[Ph,P(C,Me,H)] AND

(?15-CSMe4H)Mo(CO)(p-PPh2)2Mo[(~5-C,Me,*](CO) - 1/4&H,,

WAI-KWOK WONG*

Department of Chemistry, Hong Kong Baptist College, Kowloon, Hong Kong

FONG LUNG CHOW, HUA CHEN and BOON WA1 AU-YEUNG

Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic, Hung Horn, Kowloon, Hong Kong

and

RU-JI WANG and THOMAS C. W. MAK*

Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong

(Received 4 May 1990 ; accepted 6 August 1990)

Abstract-The phosphine ligands PhP(C,Me4H)2, I, and Ph2P(C5Me4H), II, can be pre- pared via the interaction of PhPC12 and Ph*PCl with two and one equivalent(s) of (CSMe4H)Li, respectively. At ambient temperature, C7H,Mo(C0)4 reacts with I-II to give the corresponding Mo(CO),L complex, III-IV [III, L = PhP(C,Me4H),; IV, L = PhzP(C,Me4H)], in moderate yield (6&65%). In refluxing hexane, C,H,Mo(CO), reacts with II to give (~5-C,Me4H)Mo(CO)(~-PPh2),Mo[(~5-C5Me4)P(O)Ph,](CO)~ U4GH14; V, in low yield (10%). Structures of IV and V have been determined by X-ray crystallography.

The (diphenylphosphino)cyclopentadienyl anion, Ph,P(C,H,)-, has been shown to be a very versatile reagent in organometallic synthesis. Its use as a difunctional reagent to bring two hetero metal cen- tres in close proximity has received considerable attention. ’ Although the chemistry of the anion has been investigated extensively, relatively few studies have been done on its parent compound, Ph,P(C5H5). Recently, we have demonstrated that coordinated Ph,P(C5H5) ligands in cis-M0(C0)~ [Ph,P(C,H,)J, underwent Diels-Alder dimerization to produce the 1,3_bis(diphenylphosphino) dicyclopentadiene ligand. * In this paper, we wish to report the preparation and reactivity of the tetra-

*Authors to whom correspondence should be addressed.

methylcyclopentadienyl analogues PhP(CSMe4H)2, I, and Ph2P(CSMe4H), II.

RESULTS AND DISCUSSION

Preparation of phosphine ligands

(i) PhP(C5Me4H)2, I. The interaction of PhPCl, with two equivalents of (C5Me4H)Li in hexane pro- duced a pale orange viscous oil from which white crystalline needles, I, were obtained upon cooling to -20°C. The mass spectrum of the white needles shows the highest peak at m/z 350, corresponding to the molecular ion M+[PhP(C5Me4H)2]+, and a peak at m/z 229 corresponding to the [M - (C5Me4H)]+ fragment. The 3’P(‘H} NMR spec-

2902 WAI-KWOK WONG et al.

P-Cl + _ # -CT &.)?q

P+-& pj$(

H

Scheme 1.

trum of I shows a singlet at 6 12.5 ppm. The ‘H NMR spectrum exhibits a multiplet of relative intensity 5, centred at 6 7.24 ppm for the phenyl protons ; a broad singlet of relative intensity 2 at 6 3.92 ppm for the unique protons of the two CSMe4H rings ; and three broad singlets of relative intensities 6 : 6 : 12 at 6 2.08, 1.75 and 1.61 ppm, respectively, for the methyl protons of the two &Me,H rings.

The resonance of the unique protons at 6 3.92 ppm corresponds to aliphatic rather than olefinic protons. The above spectroscopic evidence indi- cates that I is bis(2,3,4,5-tetramethylcyclopenta- 1,4- dienyl)phenylphosphine which is formed via a series of proton migrations as shown in Scheme 1.

Two structures are possible for I. These are Ia

and Ib as shown below :

Ph

10

‘P

I Ph

Ph Ib I Ph

Preparation and reactivity of PhP(C,Me,H), and Ph,P(CSMe,H) 2903

As shown in the resonance structures, steric inter- action between the two C,Me,H rings is less in Ia than in Ib. Thus, structure Ia is assigned to I.

(ii) Ph,P(C,Me,H), II. The interaction of Ph2PCI with one equivalent of (C5Me4H)Li in hexane pro- duced a thick yellow oil, II. The mass spectrum of II shows the highest peak at m/z 306, corresponding to the molecular ion, M+ [Ph2P(C,Me4H)+], and an intense peak at m/z 122, corresponding to the fragment (CfiMe4H,)+. The 3’P(‘H} NMR spec- trum of II exhibits two singlets of equal intensity at 6 -24.6 and 0.8 ppm, indicating the presence of equal amounts of the two isomers of II. The ‘H NMR spectrum exhibits a complex multiplet of total intensity 10 centred at 6 7.27 ppm for the phenyl protons, two broad singlets of equal inten- sity of total intensity 1 at 6 3.69 and 2.64 ppm for the unique proton of the C,Me4H ring, and a set of broad singlets of total intensity 12 range 6 1.54 1.91 ppm for the methyl protons of the C,Me,H ring. The appearance of two resonances at S 3.69 and 2.64 ppm for the unique proton further dem- onstrates the presence of two isomers of II. The chemical shifts of the unique protons correspond to aliphatic protons. The above spectroscopic evi- dence indicates that II is (2,3,4,5-tetra- methylcyclopenta- 1 ,Cdienyl)phosphine. Structures IIa and IIb can be assigned to the two isomers of II as shown below :

Ph2P

II0

Ph,P

Ilb

Interaction of C,H,Mo(CO), with the phosphine ligands

(i) When C7H8Mo(C0), was treated with two equivalents of PhP(C5Me,H)* at room temperature

in hexane, white crystals of stoichiometry MOM [PhP(CSMe4H)J, III, were obtained in moderate yield (60%). The infrared spectrum (KBr) of III exhibits three absorptions at 2067s, 1979s, and 1927~s (br) cm-’ at the terminal carbonyl region. The “P{‘H} NMR spectrum shows a singlet at 6 40.8 ppm. The ‘H NMR spectrum exhibits two multiplets of relative 2 : 3 intensity centred at 6 7.56 and 7.28 ppm, respectively, for the phenyl protons ; a doublet of relative intensity 2 centred at 6 4.18 ppm (Jr_‘, = 10.5 Hz) for the unique protons of the CSMe,H rings ; and three broad singlets of relative intensity 6 : 12 : 6 at 6 2.17, 1.69 and 1.50 ppm, respectively, for the methyl protons of the CSMe,H rings. The ‘H NMR chemical shift and the splitting pattern of the unique proton of the C,Me.,H rings of III is similar to that of IV which has been con- firmed by X-ray crystallography (vide infra) to be at the carbon 01 to the phosphorus. Based on the above data, the following structure can be assigned to III

(CO 15

m

Compound III is probably formed via a series of proton migrations as shown in Scheme 1 but in the reversed direction. The formation of coordinated bis(2,3,4,5 - tetramethylcyclopenta - 2,4 - dienyl) phenylphosphine reflects that in the complexed form, the 2,3,4,5-tetramethylcyclopenta-2,4-dienyl derivative is probably less sterically hindered than the 2,3,4,5 - tetramethyl - cyclopenta - 1,4 - dienyl analogue.

(ii) When C,HsMo(C0)4 was treated with two equivalents of Ph2P(CSMe,H) at room temperature in hexane, white crystals of stoichiometry Mo(CO), [PhzP(C,Me,H)], IV, were obtained in moderate yield (65%). The IR spectrum (KBr) of IV exhibits three absorptions at 207Os, 1983s, and 1927~s (br) cm- ’ at the terminal carbonyl region. The 3’P{ ‘H} NMR spectrum of IV shows a singlet at 6 37.0 ppm. The ‘H NMR spectrum exhibits two multiplets of relative intensity 4: 6 centred at 6 7.68 and 7.24 ppm, respectively for the phenyl protons ; a doublet

2904 WAI-KWOK

of relatively intensity 1 centred at 6 4.23 ppm (Jp-H = 15.3 Hz) for the unique proton of the C5Me4H ring ; and three broad singlets of relative intensity 3 : 3 : 6 at 6 1.76, 1.73 and 1.42 ppm, respectively, for the methyl protons of the CSMe4H ring. The ‘H NMR chemical shift and splitting pattern of the unique proton suggests that the proton is an ali- phatic proton and is attached to the carbon c( to the phosphorus. The above spectroscopic evidence indicates that the phosphine ligand is a (2,3,4,5- tetramethylcyclopenta - 2,4 - dienyl)diphenylphos- phine ligand. Thus, the following structure can be assigned to IV :

(CO&jMo

‘P

I Phz

The structure of IV was confirmed by X-ray crys- tallography. Crystals suitable for the diffraction study were grown from hexane. The crystal data and other parameters for the X-ray structural analysis are listed in Table 1. A perspective drawing of IV is shown in Fig. 1. Selected bond lengths and bond angles are given in Table 2. The cyclo- pentadienyl group is a planar five-membered ring (within f0.006 A). The P(l)-C(31)-C(32) angle of 111.8(4)“, together with the C-C distances of 1.52(l) A for C(31tC(32) and C(31)-C(35) as well as 1.35(l), 1.46(l) and 1.36(l) 8, for C(32)-C(33), C(33)-C(34) and C(34)-C(35), respectively, indicate that the phosphine is indeed a (2,3,4,5-tetramethylcyclo-2,4-pentadienyl)diphenyl- phosphine ligand. The molybdenum atom in complex IV retains the octahedral coordination of its parent Mo(CO),.~ The X-ray structural analysis showed that there are two distinctly different MO-C distances in complex IV. The carbonyl is tram to the Ph,P(C,Me,H) ligand and has a MO-C,,. bond of 1.989(8) 8, which is significantly shorter than the MO-C bonds involv- ing the equatorial carbonyl groups [av. MO-C,, = 2.050(9) A]. This structural feature has been observed in analogous complexes such as Mo(CO)~P(CH,CH,CN), and Mo(CO)SPPh,.4 The MO-P bond of 2.555(2) A is comparable to that found in Mo(CO)sPPh34 [2.560(l) A] but is significantly longer than those in Mo(CO),P (CH2CH2CN)34 [2.506(l) A] and Mo(CO)JP (CH2)6N3]5 [2.479(5) A]. As expected, one of the

WONG et al.

Fig. 1. A perspective view of the molecular structure of IV.

phenyl groups of Ph2P(CSMe4H) is oriented so that the P(l)-C(1 1) bond lies approximately over the bisector of an equatorial C-MO-C angle to minimize the steric interactions, which can be quan- titatively expressed by the torsion angles C(3)- Mo( l)--P( 1)-C( 11) = -43.8(4)’ and C(4)-MO (1)-P( I)--C( 11) = 49.3(4)“.

(iii) When C7HsMo(C0)4 was treated with two equivalents of I in refluxed hexane for 3 days, dark red crystals of V were obtained in low yield (10%). The IR spectrum of V in KBr exhibits two absorp- tions at 1891s and 1820s cm- ’ at the terminal car- bony1 region. The “P{ ‘H} NMR spectrum of V exhibits two singlets of relative intensity 2: 1 at 6 83.6 and 20.6 ppm, respectively. The ‘H NMR spec- trum exhibits two multiplets and a broad singlet of relative intensity 4: 8 : 18, centred at 6 7.72, 7.42 and 7.25 ppm, respectively, for the phenyl protons ; a broad singlet of relative intensity 1 at 6 5.63 ppm in the olefinic region for the unique proton of the C,Me,H ring ; and a broad singlet, two singlets, a multiplet and a singlet of relative intensity 3:3: 12:3:3,centredat6 1.91, 1.63, 1.53, 1.25and 1.08 ppm, respectively, for the methyl protons of the CSMe4H rings.

The structure of V was determined by an X-ray diffraction study of its hexane solvate, VW 1/4C6H1 4. The crystal data and other parameters for the X- ray structural analysis are listed in Table 1. A per- spective drawing of V is shown in Fig. 2. Selected bond lengths and bond angles are given in Table 3. The structure can be formulated as ($- C,Me,H)Mo(CO)(p - PPh&Mo[($ - C,Me,) P(O)Ph,](CO) and is consistent with the spectro- scopic data. Thus, the 31P chemical shifts at 6 83.4 and 20.6 ppm of relative intensity 2 : I can be assigned to the two phosphido-bridged ligands and

Preparation and reactivity of PhP(C,Me,H), and Ph,P(C,Me,H) 2905

Table 1. Data collection and processing parameters

IV V

Molecular formula

Molecular weight Colour and habit Unit cell parameters

a (A) b (A) c (A) M 0 B (“) Y (“) v (A’) Z F(OOO)

Calculated density (g cm- ‘) Space group Radiation Standard reflections Intensity variation R,,, (from merging of

equiv. reflections) Absorption coefficient (cm- ‘) Crystal size (mm3) Mean pr Transmission factors Scan type and rate (” min- ‘) Scan range Background counting Collection range Unique data measured Obs. data with IF01 2 6a(lF,l), n Number of variables, p

RF = C IlFol - IFclIP IFoI

Weighting scheme, w

Ko = [c. w(lFoI - IFcD’P Mel ‘I “2 S = E +WoI - IFcl)‘/(n -Al “’ Residual extreme in final

difference map (eA_ ‘)

(CO),Mo[(C,H,),P(C,H(CH,),)l

542.38 colourless plane

[CsH(CH3)41[C5(CH3),POPh*l .(P~,P)~Mo~(C~)~.~C,H,, (x N 0.25)

1082.45 (for x = 0.25) dark red prism

11.339(3) 13.450(3) 13.219(4) 13.457(5) 9.578(6) 15.676(3) 117.69(2) 78.27(2) 85.99(3) 76.82(2) 82.54(2) 70.94(2) 1247(l) 2585( 1) 2 2 552 1113 1.444 1.390 (for x = 0.25) Pi (No. 2) PT (No. 2)

graphite-monochromatized MO-K,, 1 = 0.71073 8,

(222), (411) (237) (3 17) f3% f2%

0.020 0.015 6.07 6.06 0.10 x 0.34 x 0.42 0.24 x 0.44 x 0.80 0.087 0.149 0.801 to 0.836 0.682 to 0.799 ~28; 3.01 to 15.63 0~28; 3.01 to 15.63

0.60 o below K,, to 0.70” above Ka, stationary counts for one-fifth of scan time at each end of scan range

h +k +I. 28,,, = 50” >_ 9-T h, f k, f 1; 20,,, = 50” 4410 9096 3687 7550 299 606 0.062 0.039

l-exp(-4sin2tI/122) 1

a2(F,)+0.00061F,12 02(Fo)+0.00005~Fo~2

0.087 0.069 1.723 4.512

+l.ll to -1.25 + 1.14 to -0.42

the phosphine oxide, respectively. The dimer can be metal-metal bond is neglected, which is similar to considered as a MO”-MO” compound. For the two that in MO&‘-CSH5)&-PPh2)2(CO)(O).* The molybdenum atoms to obey the 18-electron rule, a coordination geometries of the MO atoms in these double bond should exist between them. This is two complexes differ markedly in that the reflected by the shorter MO-MO distance of Cp( l)---Mo( 1 )-Mo(2)-Cp(2) moiety in complex 2.744(l) A in comparison with those in the anal- V is approximately linear with angles of 165.8(2)” ogous P-bridged complexes M,(C0)8(p-PEt2)26 and 179.3(2)O for Cp(l)-MO(~)-MO(~) and (M=Mo, 3.06 and M-W, 3.05) and the unbridged Cp(2)-MO(~)-Mo( l), respectively, but the cor- complex Mo~(CO)~(~~-C~H~)~’ [3.235(l) A]. The responding angles in MoA$-GHA(p- coordination polyhedron around each MO atom PPh&(CO)(O) are 124.4(2)’ and 148.5(2)“, respec- can be described as a distorted tetrahedron if the tively. The Mo2P2 core in V has the same planar

2906 WAI-KWOK WONG et al.

Table 2. Selected bond lengths (A) and bond angles (“) for IV

MoUl-P(l) 2.555(2)

Mo(l)--C(2) 2.061(8)

Mo(l)--C(4) 2.043(9)

0(1)--c(l) 1.13(l)

0(3)-C(3) 1.13(l)

0(5)-C(5) 1.12(l) P(l)-C(21) 1.846(6)

PU)_-Mo(l)_-C(l) C(l)_-Mo(lF--C(2) C( l)-Mo( 1)-C(3)

P(l)_Mo(l)--C(4) C(2)-Mo(l)--~(4) P(l)-Mo( 1)-C(5)

C(2)-Mo(l>-~(5) C(4)_Mo(lk-C(5) MO(~)-C(2)-O(2)

Mo( 1)--c(4)_-0(4) MO(~)-P(l)-C(I 1) c(l1)-P(l)-C(21)

C(1 l)_P(l)--c(31)

176.2(3) 90.3(3) 87.8(4) 90.8(2)

176.0(3) 100.4(2) 86.9(3) 89.2(4)

177.2(6) 177.6(8) 117.8(2) 98.1(3)

102.7(3)

Mo( I)-C( 1) Mo( 1)-C(3)

Mo(l>--C(5) 0(2)--c(2) 0(4)-C(4) P(l)-C(lI)

P(l)---C(31)

1.989(8) 2.043(8) 2.05( 1) 1.13(l) 1.13(l) 1.843(8) 1.867(6)

P(lF-MoUFW) P(l)---Mo(l)--C(3) C(2tMo(+C(3) C(l)_Mo(l)_C(4) C(3)_-Mo(l)--C(4) C(l)_Mo(l)_C(5) C(3)-MO(~)-C(5)

Mo(l)--C(l)_-O(l) Mo( I)-C(3)-O(3) Mo( l)-C(5)--0(5) Mo( I)-P( I)-C(21) Mo( l)-P( l)-C(31) C(21)--P(l)-C(31)

89.1(2)

88.4(3) 90.8(4) 90.0(4) 93.2(4) 83.3(3)

170.8(4) 179.0(9) 176(l) 174(l) 114.3(2) 116.1(2) 105.8(3)

(within f0.082 A from the least-squares plane) configuration as found in other analogous pho- sphido-bridged complexes. 6,8 The two carbonyl groups are tram to each other and approximately perpendicular to the Mo2P, plane. Both cyclo- pentadienyl rings are planar conjugated groups with sp2 hybridized C atoms and normal C-C bond

lengths [av. 1.428(8) A], which is in accord with the ‘H NMR results.

EXPERIMENTAL

Microanalyses were performed by Butterworth (U.K.). IR spectra were recorded on a Perkin-

P(3)

Fig. 2. A perspective view of the molecular structure of V.

Preparation and reactivity of PhP(CSMe,H)2 and Ph,P(C,Me,H)

Table 3. Selected bond lengths (A) and bond angles (“) for V

2907

Mo( l)--MO(~)

MO(~)-P(1) Mo(lF-P(2) Mo(l)--C(l) Mo(l)--Cp(l) C(l)_-o(l) P(l)_C(13) P(l)_C(l9) P(3)_-0(3) P(3)--c(51)

MO(~)-Mo( l)-P( 1) MO(~)-Mo( 1)--P(2)

P(l)_Mo(l)_P(2) Mo(2F--Mo(l)-W) P(l)-MO(~)-C(1) P(2)-Mo( I)-C( 1)

MO(~)_Mo(l)_C~(l) P(1)---Mo(l)--C~(l) P(2)_-Mo(lWp(l) C(l)_-Mo(lF--Cp(1) Mo(l)--C(l)--O(l) Mo( l)-P( l)-MO(~) MO(~)---P(l)-C(13) Mo(2FP(l)--C(13) MO(l)-P(l)-C(19) Mo(2)-P(l)-C(19) c(13)-P(lj-C(19)

O(3)_P(3)-C(8) C(8)_P(3)--C(5 1) C(8FP(3)--C(57)

2.744( 1) 2.400(2) 2.418(2) 1.928(S) 2.01 l(5) 1.157(7) 1.821(5) 1.817(6) 1.485(5) 1.821(6)

55.6(l) 55.6(l)

110.6(l) 84.9(2) 82.6(2) 84.0(2)

165.8(l) 123.8(2) 124.9(2) 109.3(2) 172.7(6) 69.4( 1)

118.3(2) 125.3(2) 124.4(2) 116.87(2) 102.1(3) 114.5(3) 103.1(3) 112.3(3)

W34’(1) MoCV--P(2) MG9--C(2) Mo(2>-Cp(2) C(2FW2) P(2)-C(25)

P(2)--c(3 1) P(3k-C(8) P(3>--c(57)

Mo( l)-MO(~)-P( 1) Mo( l)--Mo(2 )-P(2) P( l)-MO(~)-P(2) Mo( l)-MO(~)-C(2)

P(l)_Mo(2k-C(2) P(2)_Mo(2)--C(2) MO(~)-Mo(2)--Cp(2) P(l)_Mo(2)_Cp(2) P(2)_Mo(2)-Cp(2) C(2)-Mo(2)--Cp(2) Mo(2)--C(2)--0(2) Mo( l)-P(2)-MO(~) Mo( I)-P(2)--C(25) MO(~)-P(2)-C(25) Mo( l)-P(2)-C(31)

~o(2)-P(2)--C(3 1) C(25)--P(2)-C(31)

0(3>-P(3)-C(5 1) 0(3)-P(3)_C(57) C(51)-P(3)-c(57)

2.417(2) 2.425(2) 1.909(5) 2.026(5) 1.173(6) 1.834(6) 1.830(6) 1.799(5) 1.804(8)

55.0(l) 55.4( 1)

109.8(l) 70.6(2) 82.0(2) 83.5(2)

179.3(l) 124.3(2) 125.4(2) 109.2(2) 169.215) 69.0( 1)

114.9(2) 125.8(2) 128.0(2) 117.2(2) 101.7(3) 112.8(3) 111.7(3) 101.4(3)

’ Cp( 1) is the centre of the ring composed of carbon atoms C(3)-C(7), and Cp(2) is the centre of C(8)-C(12) ring.

Elmer 983 spectrometer ; data given in cm- ’ in KBr pellets. NMR spectra were recorded on a JEOL FX90Q spectrometer. Chemical shifts of ‘H NMR spectra were referenced to internal deuterated sol- vents and then recalculated to TMS = 0.0 ppm. “P NMR spectra were referenced to external 85% H3P04. Mass spectra were obtained on a VG7070F spectrometer.

All operations were carried out under nitrogen or in uacuo. All chemicals used were of reagent grade. Solvents were dried by standard procedures, distilled, and deaerated prior to use. Melting points were taken in sealed capillaries and are uncorrected.

C5Me4HT9 and C7H8Mo(C0)4’0 were prepared according to literature methods.

Preparation of PhP(CSMe4H)*, I

A three-necked round-bottom flask (250 cm3) fitted with a gas inlet, magnetic stirring bar and

pressure-equalizing addition funnel was charged with 1,2,3,4-tetramethylcyclopentadiene (5.4 g, 44.3 mmol). Anhydrous tetrahydrofuran (100 cm3) was syringed into the flask. The solution was then cooled to about -5°C and n-BuLi (26 cm3, 1.6 M, 41.6 mmol) was added dropwise to the solution over a period of 1 h. During the period, a white precipitate was formed. The reaction mixture was then warmed to room temperature slowly and allowed to stir overnight. The mixture was cooled to - 78°C. Dich- lorophenylphosphine (2.8 cm3, 20 mmol) was then added dropwise to the solution. The white pre- cipitate gradually disappeared and the solution changed to clear yellow. The solution was then warmed to room temperature and stirring was con- tinued for another 2 h. The solvent was removed in vacua. The residue was extracted with hexane (2x 50 cm’). The combined hexane filtrate was evaporated in uacuo to give a pale orange viscous oil from which white needles were obtained upon

2908 WAI-KWOK WONG et al.

cooling to -20°C. Yield (pale orange oil) : 5.6 g, 80%.

‘H NMR (CDCI,): 6 7.24 (m, 5H), 3.92 (br s, 2H), 2.08 (br s, 6H), 1.75 (br s, 6H), 1.61 (br s, 12H); 3’P{ ‘H} NMR (CDC13) : 6 12.5(s) IR(neat, cm- ‘) : 3053m, 2963s 2912s 2855s 2738w, 1955w, 1813w, 1584w, 1544w, 1479w, 1433s 1378s 1326w, 1302w, 1253w, 1215m, 1183m, 1140m, 1109m, 1088m, 1068m, 1025m, 976s, 897w, 844m, 794w, 744s, 7lOm, 696s, 633w, 566m, 539m, 514m, 486m. MS : m/z 350. The purity of the pale orange oil was judged to be 95% by “P{ ‘H} NMR.

Preparation of Ph2P(CSMe,H), II

The procedure was the same as the preparation of I. C5Me4H2 (4.1 g, 33.6 mmol), n-BuLi (1.6 M, 20 cm3, 32 mmol) and PhlPCl (7.0 g, 31.7 mmol) were used. A pale orange oil was obtained. Yield : 8.0 g, 72%. ‘H NMR (CDCI,): 6 7.27 (m, 1.0 H), 3.69 and 2.64 (two br s of total lH), 1.54-1.91 (sets

ofs, 12H); 3’P{ ‘H) NMR (CDCl,) : 6 -24.6 and 0.8 (two s of equal intensity). IR (neat, cm-‘): 3068m, 3052m, 2963s 2916s 2872s 1948w, 1883w, 1808w, 175Ow, 1583m, 1478m, 1431s 1327m, 1304m, 1274w, 1216m, 118lm, 1156m, 1130m, 1093s 1068m, 1026m, 999s 980s 895m, 846m, 79lw, 740s 696s. MS: m/z 305. The purity of the pale orange oil was judged to be 90% by “P( ‘H} NMR.

Preparation of Mo(CO)JPhP(C5Me4H)J, III

A solution of C,H,MO(CO)~ (1.15 g, 3.8 mmol) in hexane (50 cm3) was added dropwise to a solution of I (2.8 g, 7.9 mmol) in hexane (20 cm’). The solution was allowed to stir at room temperature for 18 h. The solution was filtered. The filtrate was concentrated to ca 20 cm3 and chromatographed on silica gel under nitrogen atmosphere using hex- ane as eluent. A pale yellow band was separated. The solution was concentrated to ca 20 cm3 and cooled to -20°C to give white needles which were filtered and dried in vacua. Yield : 1.3 g, 60% ; m.p. 113-l 15°C [Found (required): C, 59.6(59.4); H, 5.4(5.3); P, 5.2(5.3)]. ‘HNMR(CDC1,): 67.56(m, 2H), 7.28 (m, 3H), 4.18 (d, Jr_” = 10.5 Hz, 2H), 2.17 (br s, 6H), 1.69 (br s, 12H), 1.50 (br s, 6H) ; 3’P{ ‘H} NMR (CDC13) : 6 40.8(s). IR in KBr, vco : 2067s 1979s and 1927~s (br) cm- ‘.

Preparation of Mo(CO)SIPhzP(C,Me,H)], IV

A solution of C,H,Mo(C0)4 (1.7 g, 5.7 mmol) in hexane (50 cm’) was added dropwise to a solution of II (3.6 g, 11.6 mmol) in hexane (20 cm3). The

solution was allowed to stir overnight at room tem- perature, upon which a brown solution was obtained. The solution was filtered and the filtrate was evaporated to dryness in vacua. The residue was then dissolved in a minimum amount of toluene and then chromatographed on silica gel using tolu- ene as eluent. A brown band was collected. The solution was evaporated to dryness in vacua. The residue was re-dissolved in a minimum amount of toluene and chromatographed on silica gel using hexanetoluene (10 : 1) mixture as eluent. A light yellow band and a crimson band were obtained. The solvent of the light yellow band was removed in vacua. The residue was dissolved in a minimum amount of toluene, and hexane was added until it started to turn cloudy. At this point, a small amount of toluene was added to make the solution clear again. The resultant solution was then cooled to -20°C to give white crystals which were filtered and dried in vacua. Yield : 2.0 g, 65% ; m.p. 152- 154°C (decomp.) [Found (required) : C, 57.6(57.6) ; H, 4.3(4.2); P, 5.2(5.7)]. ‘H NMR (CDCI,): 6 7.68 (m, 4H), 7.24 (m, 6H), 4.23 (d, JP_-H = 15.3 Hz, lH), 1.76 (br s, 3H), 7.24 (m, 6H), 4.23 (d, JPpH = 15.3 Hz, lH), 1.76 (br s, 3H), 1.73 (br s, 3H), 1.42 (br s, 6H) ; 3 ‘P{ ‘H} NMR (CDCI,) : 6 37.0 (s). IR in KBr, vco: 2070s 1983s 1927~s (br) cm _ ‘.

Attempts to isolate products from the crimson band were unsuccessful.

Preparation of V

A solution of C,H,Mo(C0)4 (0.9 g, 3.0 mmol) in hexane (50 cm3) was added dropwise to a solution of II (2.0 g, 6.5 mmol) in hexane (20 cm3). The solution was refluxed for 3 days. A dark solution with dark precipitate was obtained. The solution was filtered. Attempts to isolate crystalline product from the filtrate were unsuccessful. The dark pre- cipitate was dissolved in a minimum amount of toluene, and chromatographed on silica gel using toluene as eluent. An orange-red band was obtained. The solvent of the orange-red band was evaporated to dryness in vacua to give a dark red residue. The residue was then re-dissolved in a mini- mum amount of methylene chloride, and hexane was added until it started to turn cloudy. At this point, a small amount of methylene chloride was added to make the solution clear again. The result- ant solution was allowed to evaporate slowly in air. After two days, dark red prisms of stoichiometry C,,H,,03P3M02* 1/4(C6H14) were formed. They were filtered and dried in vacua. Yield : 0.2 g, 12% ; m.p. > 300°C [Found (required) : C, 64.0(63.8); H, 5.7(5.4); P, 8.2(8.6)]. ‘H NMR (CDC13): 6 7.72 (m, 4H), 7.42 (m, 8H), 7.25 (br s, 18H), 5.63 (br s, lH),

Preparation and reactivity of PhP(CSMe4H)2 and Ph2P(CSMe.,H) 2909

1.92 (2x s, x9]> 2.63 (f, ?H), 2.5? (q 2229, 2.25 (a?> SHEL7X222.US prugram package" on a DEC 3H), 1.08 (s, 3H) ; 3’P{ ‘H} NMR (CDC13) : 6 83.6 MicroVAX-II computer. Analytic expressions of

(s, 2P), 20.6 (s, 1P). IR in KBr, vco : 1891s and 1820s atomic scattering factors were employed, and cm- ‘. anomalous dispersion corrections were incor-

porated. I4

Raw intensities collected on a Nicolet R3m/V four-circle diffractometer at room temperature (294 K) were processed with the profile-fitting procedure off Diamond” and corrected For abso@ion usins *-scan data.‘2 I&& of data cdlection and pro- cessing for complexes IV and V ax kted in T&k 1.

Acknowledgement-We thank the Hong technic and UPGC for financial support.

Kong Poly-

(i) Complex IV. Patterson superposition yielded the positions of all non-hydrogen atoms which were subjected to anisotropic refinement. The hydrogen atoms were generated geometrically (C-H bonds fixed ar 0.96 &j and allowed to tide on their respec tive parent C atoms; all hydrogen atoms were as&& aFfwp+iiate 'kdi@C $~l-~a’ssli~ fac%a+is and included in the structure-factor calculations.

(ii) Complex V. The Mo2P2 core was located by direct phase determination and the coordinates of the other non-hydrogen atoms were derived from successive difference Fourier syntheses. A dis- ordered n-hexane solvent molecule located about a crystallographic inversion centre was found on a subsequent difference Fourier map, and interatomic distance constraints of 1.500(2) and 2.490(2) A were applied to pairs of adjacent and alternate carbon atoms, respectively. The occupancies of these carbon atoms were fixed at l/2 in the refinement to be compatible with reasonable values of their tem- perature factors. All non-hydrogen atoms were sub- jc&& <a ~%&z;_fliz &&~E&. ~y&ifiz~, ~Qflza except those of the solvent molecule were generated geometrically (C-H bonds fixed at 0.96 A) and allowed to ride on their respective C atoms; they were assigned appropriate isotropic temperature factors and included in the struc~~~e-fac~0r ca\- culations.

4.

5.

6.

I.

8.

9.

10.

11. 12.

13.

14.

Computations were performed using the

G. K. Anderson and M. Ljn., Or~~~~~e~~lI~ccs 1988, 7, 2285, and refs therein. W. K. Wong, F. L. Chow, H. Chen and T. C. W. Mak, J. Organomet. Chem. 1989,377, C65. W. Riidorff and U. Hoffmann, Z. Phys. Chem. (B) 1935, 28, 351; T. C. W. Mak, Z. Kristallogr. 1984, 166,277. F. A. Cotton, D. J. Darensbourg and W. FT. Ifsfey, fnorg. Chem. I981,20, 578. 5. zt. ~LelIi0, L. QI Tz&-mi3, %%. Y. I)“as~f3%q and R. J. Majeste, Inorg. Chem. 1976, 15, 816. M. H. Linck and L. R. Nassimbeni, Znorg. Nucl. Chem. LBtt. 19?3,9, 1105. R. D. Adams, D. M. Collins and F. A. Cotton, Znorg. Chem. 1974,13, 1086. W. K. Wong, F. L. Chow. H. Chen, R.-J. Wang and T. C. W. Mak, Polyhedron 1990,9,2469. C. tif. ~~‘t~rick, L. D. Si&X-&, v. w’. Ddy tIfId T. J.

Marks, Organometallics 1988, 7, 1828. J. J. Eisch and R. B. King, Organometallic Synthesis, Vol. 1, pp. 124125. Academic Press, New York (1965). R. Diamond, Acta Cryst. A 1969, 25, 43. G. Kopfmann and R. Hubber, Acta Cryst. A 1968, 24,348. G. M. ShsJdrj& Jo C~~u~~JJqvz@.Lc C&qut_iq 3: Data Collection, Structure Determination, Proteins and Databases (Edited by G. M. Sheldrick, C. Kruger and R. Goddard), p. 175. O.U.P., New York (1985). International Tables for X-ray Crystallography, Vol. IIr, pp. 55, 99 anct 149, Xynoch Press, Birmingham (1974). (Now distributed by Kluwer Academic Pub- lishers, Dordrecht.)