Oxidative addition of methyl iodide to bis(phenyl)(chelate)platinum(II) complexes

C25

Journal of Organometallic Chemistry. 105 (1976) C25-C26 o Elsevier Sequoia S.A., Lausanne -Printed in The Netherlands

Preliminary communication

OXIDATIVE ADDITION OF METHYL IODIDE TO BIS(PHENYL)(CHELATE)PLATINUM(II) COMPLEXES

R. US6N*,

J. FORNIlk,

Department

P. ESPINET

of Inorganic Chemistry,

and J. GARiN

Uniuersity of Zaragoza (Spain)

(Received November 17th, 1975)

Summary The oxidative addition of Me1 to Ph*Pt(chel) (chel = bipy, phen) leads to IMePh,Pt(chel); these iodine complexes are very stable, and can be isolated and used for the synthesis of the stable complexes XMePh,Pt(phen). via substitution reactions with thallium or silver salts MX (X = Cl, Br, CN, SCN, CNO, N3)_

The oxidative addition of Me1 to organoplatinum(I1) complexes of the RzPtLl type readily takes place for R = alkyl, but not for R = aryl [l] .The formation of iodine complexes, such as IPh,MePtL, (L = PPh,Me), in solution was recently described [a], but the complexes could not be isolated because of decomposition to toluene and trans-IPhPtL,. The different behaviour of alkyl and aryl platinum(I1) complexes could be due to dissimilarities in the bonding of the platinum atom, which in atyl complexes acts 133 as both a cr-and n-donor. The oxidative addition of MeI would give rise to a decrease of the electron density on the platinum atom and in consequence to a weakening of its donor capacity. The experiments described in refs. 1 and 2, were carried out with platinum(I1) complexes with phosphine or amine ligands. We have now examined the oxidative addition of Me1 to complexes having ligands which are better edonors and worse n-acceptors, such as l,lO-phenanthroline and 2,2’-bipyridine. The starting complexes (&H,),Pt(chel) were made by treating ClzPt(chel) with an excess of &H,MgBr [4]. The complexes were added to stirred Me1 at room temperature,

(C6H&Pt(chel) + CH31 ------+

ICH3(C6H,)2Pt(chel)

11)

and the resulting products were obtained as yellow crystals, which are air-stable

*To

whom correspondence should be addressed.

_. ..

::..‘l.

-:

::.

:‘.at ‘rodin_t@npetitur~a&do ntit d&onipose below 200%. All productsg&e .‘. :; &.&fac&,~ ~,.H.~d_N~~y~es;~ .. I .’ -- _, .. .:. :_.Theiodinka&i may be substitutedby other hdogens &or pseudohaogens : aG%dinij

to

eq. 2: The &actions t&e pke mdre qu+y

:’ :. ICH&~H,),Pt@hen) -1:(M

i MX _

withsilver salts,

MI + XCH&&,)&$phen)

=.‘I?, Ag; X .=.a, k!r, CN, S&N, CNO, N3) .

:..’

(2) .,

esljecia&if &e&a& &shly~pr&pitate~ and m&st. The reporkd comfilexesare the first of this type. The &de complex is :. especi.@y notWorth$, since only fmo other platinum(IV) azide complexes .. ire known, viz. [Pt(N&] *- and [ivie,Pt(N,)] 4 [5,6]. Fkferences 1 J. Chatt and B.L. Shaw. J. Chem. Sac.. (1959) 4020. 2 T.G. Appl+m. H.C. Clark and L.E. Manner, J. Organametal, Chem.. 65 (1974) 275. 8 Ni Cha~dhur~. and R.J. Puddephatt, J. Organometal. Chem.. 84 (1975) 106 and ref. therein. 4 P. B&net, Doctoral The&, University of Zaragoza, 1976. 5 W. Be& E. Schmiemr and K Feld. Angew_ Chem.. 78 (1966) 267. 6 K.H. VOW Dg&len and I Lorberth. J. OrganametaL Chem_, 65 (1974) 267.