Vol. 7, No. 11, November 1968
COMPLEXES OF TRIVALEKT PHOSPHORUS DERIVATIVES2353 CONTRIBUTION FROM THE DEPARTMENT OF CHEMISTRY, UNIVERSITYOF GEORGIA,ATHENS,GEOXGIA 30601
Complexes of Trivalent Phosphorus Derivatives. VI. The Unsymmetrical Cleavage of Binuclear Cyclopentadienylmetal Carbonyls with Chelating Ditertiary Phosphines' BY R. B. KING,2'3 K. H . PANNELL,4 C. A. EGGERS,4 AND L. W. HOUK4
Received April 17, 1968 The cyclopentadienylmolybdenum carbonyl [CsHsMo(CO)a]nundergoes unsymmetrical cleavage upon reaction with chelating ditertiary phosphines in hydrocarbon solvents a t room temperature to give yellow ionic products of the type [CsHsMo(CO)z(diphos)][GH5Mo(CO)a] (diphos = R2PCHnCH2PR2 or cis-(C6Hl)zPCH-cHP(C6Hs)2; R = CH3 or CeHs). The c y clopentadienyliron carbonyl [CsHsFe(C0)2]~ undergoes unsymmetrical cleavage upon reaction with the methylated chelating ditertiary phosphine (CHa)2PCH2CHJ?(CHa)2in hydrocarbon solvents at room temperature to give orange pyrophoric ionic [C~H~F~(CO)(CH~)ZPCHZCHZP(CHI)~] [CjHsFe(C0)2]; this is the first solid salt of the very reactive CsHjFe(CO)2- anion t o be isolated. Other salts of cations of the types CjH5M0(CO)~(diphos)* and CiHsFe(CO)(diphos) + with chloride or hexafluorophosphate anions have also been prepared.
Metal carbonyls react with trivalent phosphorus types C5H5V(CO)(PR3) C5H&fn(CO) (PR3)3-n, lo ligands in two distinctly different manners5 In most or C6H5Co(CO)(PRI), respectively. The binuclear cyclopentadienylmetal carbonyl [CSH~MO (CO)312 cases these phosphorus ligands form nonionic products when treated with triphenylphosphine in boiling tetraby replacement of one or more carbonyl groups in a hydrofuran undergoes a substitution reaction without substitution reaction. Thus, Cr(CO), reacts with triscleavage of the metal-metal bond giving the binuclear (dimethy1amino)phosphine (tdp) to give the nonionic derivative (C5H5)zMoz(C0)5P(C6H5)3. l2 All of these product t d ~ C r ( C 0 ) ~However, .~ in a few cases binuclear metal carbonyl derivatives, particularly C O ~ ( C O ) ~ , reported reactions of cyclopentadienylmetal carbonyls may be regarded as simple substitution reactions. This undergo disproportionation to form ionic products conpaper reports some disproportionation (unsymmetrical taining a cation with the metal in a formal positive oxidation state and an anion with the metal in a formal cleavage) reactions of the binuclear cyclopentadienylmetal carbonyls [CE,H~MO(CO)~]~ and [C5H5Fe(C0)212. negative oxidation state.' A good example of this disAfter completion of this work, a paper appeared by ) ~ trisproportionation reaction is that of C O ~ ( C Owith Haines, Nyholm, and Stiddard,l 3 which described the (dimethy1amino)phosphine to give the salt [(tdp)zCosimilar unsymmetrical cleavage of [CsHsMo(CO)3 1 2 (CO)3][CO(CO),].~ This type of disproportionation with various tertiary phosphines to give the similar salts reaction of a binuclear metal carbonyl derivative with a Lewis base such as a tertiary phosphine may be re[C&MO(CO)zLz] [CSHBMO(CO)S](L = (czHs)~P, garded as an unsymmetrical cleavage reaction analo(C4Hg)3P1 and (CeH5)3P or Lz = (C6H6)zPCH~CHJ'gous to the unsymmetrical cleavage of diborane, B2Hs, (C6H5)2 ) . with Lewis bases to give ionic products of the type Experimental Section [LzBH2][BH4].8 The unsymmetrical cleavage of biMicroanalyses (Table I) were performed by Pascher Mikronuclear metal carbonyls with tertiary phosphines conanalytisches Laboratorium, Bonn, Germany. Combustion trasts with the familiar symmetrical cleavage of binuanalyses for carbon, hydrogen, and oxygen on some of t h e clear metal carbonyls with reagents such as the halogens products gave erratic results. Infrared spectra were takeri in potassium bromide pellets and recorded on a Perkin-Elmer or the alkali metals to give mononuclear products such Model 621 spectrometer with grating optics. as the corresponding metal carbonyl halides or anions. A nitrogen atmosphere was always provided for the following The reactions of cyclopentadienylmetal carbonyls three operations: (a) carrying out reactions, (b) handling all with trivalent phosphorus ligands have been much less filtered solutions of metal complexes, and (c) admitting to evacuinvestigated. The mononuclear cyclopentadienylated vessels. In addition, the metal carbonyl anion salts were filtered under a nitrogen atmosphere and the pyrophoric salts metal carbonyls C5H,V(CO)4, C5H5Mn(C0)3, and containing both metal carbonyl anions and 1,2-bis(dimethylC5H5Co(C0)2(or their simple derivatives) react with phosphin0)ethanemetal carbonyl cations were transferred in a tertiary phosphines to give substitution products of the nitrogen-filled polyethylene glove bag. q-n,6j
(1) Part V: R. B. King and K. H. Pannell, Inoug. Chem., 7, 1510 (1968). (2) Fellow of the Alfred P. Sloan Foundation, 1967-1969. (3) Author to whom inquiries should be addressed a t the University of Georgia. (4) Postdoctoral fellows supported by the Air Force Office of Scientific Research a t various times during the period Nov 1966-Aug 1968. (5) For a review of the reactions of metal carbonyls with trivalent phosphorus ligands, see T.A. Manuel, Advan. OYganometaL Chem., 8 , 181 (1965). (6) R.B.King, Inorg. Chem., a, 936 (1963). (7) For a review article containing many examples of disproportionation reactions of this type, see W. Hieber, W. Beck, and 0.Braun, Angew. Chem., l a , 795 (1960). (8) R . W. Parry and L. J. Edwards, J . A m . Chem. Soc., 81, 3554 (1959); G. Kodama and R . W. Parry, ibid., 81, 3534 (1959); 81, 6250 (1960).
Reagents.-The
chelating ditertiary phosphine ligands were
(9) E. 0. Fischer and R. J. J . Schneider, Angew. Chem. Intern. E d , Etzgi., 6, 569 (1967).
(10)(a) J. Lewis, R. S . Nyholm, A. G.Osborne, S . S. Sandhu, and M. H. B. Stiddard, Chem. Ind. (London), 1398 (1963); (b) R . G. Hayter and L. F . Williams, J . Inorg. Nucl. Chem., '26, 1977 (1964). (11) (a) R . B. King, Inorg. Chem., 6, 82 (1966), (b) H. G. SchusterWoldan and F . Basolo, J. A m . Chem. Soc., 88, 1657 (1966). (12) K. W. Barnett and P. M . Treichel, Inorg. Chem., 6, 294 (1967). (13) R . J. Haines, R . S. Nyholm, and M. H. B . Stiddard, J. Chem. Soc., A , 43 (1968).
2354
Inorgmic Cheinistvy
KING, PAXXELL, EGGERS, A N D HOCK ’I‘ABLE 1 NEW COMPOUXDS PREPARED I N THIS WORK
-
Analsses,
