Thermally stable complexes

The reaction of [Cr(NH3)5H20](C104)3 and NaN3 in dilute acetic acid solution at 60 °C affords the monoazido complex [CrN3(NH3)s](C104)2.647 The addition of less than one equivalent of KN3 to a solution of chromium(III) in molten KCNS at 185 °C produces a bathochromic shift in the visible spectrum consistent with the formation of the thermally stable complex [Cr CSJsNj3-.648 The neutral triazido complexes Cr(N3)3(NH3)3 and Cr(N3)3(py)3... 

The crystalline, thermally stable complex Me5C5PNH Bu+AlClJ was recently described E. Niecke and D. Gudat, in preparation. 

Both cadmium and mercury compounds M[SnR3]2 (R = Me, Et, Pr, f-Bu, Ph) are oxidized by air to the related stannoxanes and MO (M = Cd) or M (M = Hg)239,241. Peroxides, e.g. Bz202, also perform similar oxidations to form M(OBz)2(M = Cd) and BzOSnR3365. Even the thermally stable complexes with bulky ligands (R = Me3SiCH2) are also oxidized333. 

Metal fragments of the form (TpRe(CO)(L), in which L = Melm or NH3, have the ability to bind substituted benzenes in an 2-fashion. The fragment having L = Melm has seen more application because of difficulties associated with the synthesis and isolation of aromatic complexes having L = NH3. Anisoles, phenols, and naphthalenes all form thermally stable -complexes when stirred in excess (10-25 equiv.) with TpRe(CO)(MeIm)( /2-benzene) in THF. The complexes are typically isolated by precipitation from hexanes. The benzene complex can be prepared by direct reduction of the Re(III) precursor, TpRe(MeIm)(Br)2, with Na° in benzene under one atmosphere of CO [35]. 

HS form thermally stable complexes with transition metals, among others with iron and chromium. On irradiation the Fe (III) complexes undergo photoreduction producing Fe(II) and organic radicals (6,14). 

Homoleptic alkyl and aryl complexes of vanadium(IV) can in principle be synthesized from VCI4. However their thermal instability of makes them difficult to isolate. In some cases, the use of lithium alkyls and alkyl Grignards leads to reduction from V(IV) to V(III). Interestingly, [V(l-norbornyl)4], prepared from VCI4 and Li(l-norbornyl), is relatively stable up to 100 °C and is only moderately air sensitive [30]. The most air/ thermally stable complex of this class is [V(Mes)4], which was isolated in nearly quantitative yield by air oxidation of Li[V(Mes)4] [31]. 

The asymmetric Jt-basic moiety [Re(Tp)(CO)(Meim)] gives thermally stable complexes with ethyl acetate, acetic anhydride, N-methylsuccinimmide, N-acetylpyrrole, and N-methylmaleimide. X-ray and NMR data for [Re(Tp)(CO)(Meim)(T]2-N-methyl-succinimide)] have also been reported.222... 

These interesting phthalocyanine aluminosiloxanes are insoluble, thermally stable complexes which sublime unchanged. The backbones, which are... 

In the presence of tricyclohexylphosphine, Ni-diene condensations form Cg-containing ( -bis(a]lyl) complexes. Treatment of the tricyclohexylphosphine adduct of (cyclododecatriene)Ni with 1,3-dienes affords thermally stable complexes having the stoichiometry Ni(diene)2P(C6Hu)3 From IR and NMR studies and the structure of the isoprene derivative , these complexes contain the S)j -bis(allyl) structure, both in the solid state and in solution ... 

Because these dehydrogenation reactions occur at high temperatures, catalyst stability limits turnover numbers. The development of so-called pincer ligands, which are tridentate anionic ligands that give rise to thermally stable complexes, has led to the... 

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