摘要：

J. CHEM. SOC. DALTON TRANS. 1994 2197Synthesis of Cationic Half -sandwich Rhodium(i) Complexesof 1,4,7=Trithiacyclononane ([SIaneS,). The Single-crystalStructures of [Rh([9]anes3)(c2H4),]PF6, [Rh( [9]aneS,)-( C,H ,2)] B F, and [ R h ( [g] an&,) ( C,H,)I P F6*0.250 Et, tAlexander J. Blake, Robert 0. Gould, Malcolm A. Halcrow and Martin Schroder"Department of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UKReaction of [Rh,~L',CI,] {L, L' = C,H4,30d or4nbd; L = C,H,, L' = PPri, or P(C,H,,),; cod = cycloocta-1 ,5-diene, nbd = norbornadiene (bicyclo[2.2.1] hepta-2,5-diene)} with 2 molar equivalents of 1,4,7-trithiacyclononane( [9]aneS,) in the presence of NaBF, or NH,PF, at 293 K, or treatment of [Rh(C,H,),CI]or [Rh(CO)CI(PPh,),] with 1 molar equivalent of [9]aneS, and NH,PF, afforded [Rh( [9]aneS,)L(L')]X[L, L' =C,H,.%od, $nbd or2$,H,; L = C,H,.L' = PPr',. P(C,H,,),; L = CO, L' = PPh,; X = BF, or PF,] inmoderate yields. The crystal structure of the complex [Rh( [9]aneS,) (C,H,),] PF, has been determined:monoclinic, space group P2Jn. a = 11.487(3), b = 9.459(3), c = 15.745(6) A, p = 105.54(3)" and Z =4. The cation adopts a trigonal-bipyramidal geometry, with one equatorial an! one axial ethene ligand.The complex [Rh( [SIaneS,) (cod)] BF, crystallises in the triclinic space group P1 with a = 11.491 (1 3). b =12.803(6), c = 13.377(15), u = 88.1 2(7), f! = 70.30(8), y = 74.68(7)' and Z = 4. The two molecules ineach asymmetric unit also adopt distorted trigonal- bipyramidal stereochemistries, with the conformation inmolecule 1 being related to that of molecule 2 by a 6" rotation of the macrocyclic ring about the centralM-[9]aneS, axis.The complex [Rh( [SIaneS,) (C,H,)] PF, crystallises in the monoclinic space group C2/cwith a = 18.61 2(6), b = 8.679(5), c = 23.756(5), p = 96.844(18)" and Z = 8. The structure shows aquasi-square-pyramidal complex cation. Treatment of [Rh,(CO),CI,] with [9] aneS, and NH,PF, yieldedthe dimeric complex [Rh,( [9]aneS3),(p-C0),] [PF,],. Reaction of [Rh( [SIaneS,) (C,H,)L] + [L = C,H, orP(C,H,,),] with halogenatcd substrates afforded insoluble [Rh([S]aneS,)X,] (X = CI or I), while noreaction was observed with C,H, or SiEt,H. Spectroscopic, structural and chemical evidence indicates thatthe [Rh( [9]aneS,)] + fragment has a high electrophilic character.The chemistry of half-sandwich rhodium(1) and iridium@complexes containing tridentate facially binding ligands such astris(pyrazolyl)borates, P,O,,- and the tripodal phosphinesX(CH2PPh2j3 (X = N, P or CMe) as protecting groups is ofwide i n t e r e ~ t .' ~ ~ Such compounds are isoelectronic with thewell known [Rh(C,R,)L2] (R = H or Me; L = alkene, COor PR,),' the photochemistry of which has been the subject ofseveral investigations. Both the cyclopentadienyl complexesand their analogues have been shown to exhibit novel reactivity,particularly towards C-H bonds. For example, the unsaturatedfragments [M(C,Me,)L] (M = Rh or Ir; L = C,H,, CO orPMe,) generated by the low-temperature photolysis of[M(C,Me,)L,] (L = C2H4 or CO) or [M(C,Me,)(PMe,)H,]oxidatively add across a range of alkane, alkene and arene C-Hbonds,6 while [Rh(HB(pz),)L,] (pz = pyrazolyl; L =C,H4 or CO) undergo the same type of reaction under mildthermal conditions.' As part of our studies of the chemistry ofthe crown thioethers,' we argued that the small-ring macrocycle1,4,7-trithiacyclononane ([9]aneS3) could also act as aprotecting group analogous to the cyclopentadienyl ligand, andthat the complexes [Rh([9]aneS3)L2]+ (L = C2H4, CO orPR,) might exhibit novel chemistry.This paper describes thesynthesis and structures of several such compounds, togetherwith a preliminary study of their reactivity.We and others have investigated the chemistry ofrhodium(rI1) with thioether crowns.''-I2 In particular, we haveshown that the octahedral hexathia cation [Rh([9]aneS,)2]3 +t Supplementary data available: see Instructions for Authors, J. Chem.Soc., Dalton Trans., 1994, Issue 1, pp. xxiii-xxviii.can be r

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