CARBENE COMPLEXES .24. PREPARATION AND CHARACTERIZATION OF 2 ENETETRAMINE-DERIVED CARBENERHODIUM(I) CHLORIDE COMPLEXES RHCL(L(R))(3) AND [RHCL(COD)L(R)] (L(R)=DCN(ME)CU(CH)(4)CNME-O) AND THE PREPARATION AND X-RAY STRUCTURES OF THE ENETETRAMINE L(2)(R) AND ITS SALT [L(2)(R)][BF4](2)

The enetetramine [o-C6H4{N(Me)}C-2](2) (abbreviated as L(2)(R) (1) has been obtained either from N,N'-dimethyl-o-pbenylenediamine and CH(OMe)(2)NMe(2) or from [o-C6H4{N(Me)}C-2]I and NaH. Treatment of 1 with Ag[BF4] yielded the salt [L(2)(R)][BF4](2) (2). Use of L(2)(R) and [{Rh(mu-Cl)(COD)}(2)] in appropriate stoichiometry gave the carbenerhodium(I) chlorides [RhCl(COD)L(R)] and RhCl(L(R))(3); Rh-103 NMR chemical shifts for 3 and 4 have been recorded. Crystal structure determinations were carried out on compounds 1 and 2. The most notable features are the differences between 1 and 2 with respect to (i) the C-C bond length [1.344(4) Angstrom (1) and 1.462(13) Angstrom (2)], (ii) the adjacent endocyclic N-C bond length [1.428(8) Angstrom (1) and 1.331(4) Angstrom (2)], (iii) the torsion angle about the central C-C bond [21 degrees (1) and 72 degrees (2)] and (iv) the closer approach of the nitrogen environment to trigonal planar in 2 than in 1.