Imino complexes

The reaction between Ni(cod)2 and iminobenzophenone has been carried out as outlined in equation (33).192 The bis-imino complex (36) is trinuclear in the solid state containing bridging, terminal, end-on and side-on coordinated imino groups. 

Similarly, the more stable imino-complexes Cl2(NAr)(PX3)2W(>/2-3,3-C3R2H2) undergo facile ring cleavage reactions to the corresponding vinyl alkylidene complexes under... 

Gold(I) isonitrile complexes were first reported (131) in 1956, when it was found that they were generally less stable than the isonitrile complexes of other transition metals. This was attributed to the low tendency of gold to form bonds with double bond character. A number of isonitrile complexes have been made, however, and they have been used extensively in the preparation of carbene and imino complexes of gold(I). 

In addition, the imino complex was subject to trapping by NaBH3CN. The electron-withdrawing power of the imine or its N-protonated form are superior to the ketone in providing as much as a millionfold rate acceleration compared to the spontaneous reaction. 

Treatment of [W(N2)2(PMe2Ph)4] with HCl under CO afforded [W (NNH2)(CO)(PMe2Ph2)Cl2], which reacted with 2,4,6-trimethylpyrylium tetrafluoroborate in the presence of HCl giving the (l-pyridino)imino complex [W (NNC5H2Me3)(CO)(PMe2Ph)2]+. 

Isonitrile is isoelectronic with CO, and iminoacyl complexes can be compared with acyl ones. The most remarkable difference is that isonitrile undergoes multiple insertion, not observed in CO, into transition-mctal-carbon bonds to produce bis-, tris- or poly(imino) complexes . ... 

The imino complexes are prepared by (i) insertion into complexes containing a metal-carbon bond, (ii) oxidative addition of RX to zero-valent isonitrile complexes and subsequent insertion of the coordinated isonitrile, (iii) nucleophilic reaction of R with halogeno-metal isonitrile complexes and (iv) reaction of anionic isonitrile complexes with alkyl halides. 

The reaction of benzonitrile, Bu Li and lead(II) chloride is the unexpected (THF)Li[ (Ph)-(Bu )C = N 3Pb], a rare lead imino complex, in which the alkyl lithium reagent has added across the nitrile triple bond and generated a lithium imide that has reacted in situ with the lead(II) chloride. The anionic complex has a pyramidal geometry at the lead, and in the solid state, the lithium ion bridges the three nitrogens on the opposite face to the lead. ... 

Polymerization reaction of isocyanides RNC is catalyzed by [Fecp(CH2Ph)(CO)]. It proceeds as a result of multistep migration to coordinated ligands and is evidenced by the isolation and identification of the tris(imino) complex (9.164). " ... 

In 2006, Abu-Omar reported on stop-flow studies of the reactions of the soluble ArlNTs reagent ( Ar=ort/i )- BuS02C6H4), an analogue of the soluble iodosylarene described above, with the manganese corrole complex [(tpfc)Mn (EtOAc)] (tpfc=5,10,15-tris(pentafluorophenyl)corrole (Scheme 19) [82]. [(tpfc) Mn(EtOAc)] can catalyze the reaction of PhINTs with styrene to form aziridines. In this study, an initial adduct of the ArlNTs with Mn corrole leads to a detectable mono-adduct [(tpfc)Mn N(Ts)FAr ] (Scheme 16). The initially formed adduct then loses ArI to form an isolable Mn imino complex [(tpfc)Mn(=NTs)]. This imino complex, however, is not the active catalyst for imino transfer to olefins. 

Scheme 4.4 Site-selective incorporation of D-atom reveals the intermediacy of a reactive imino complex...

Figure 12.2 Calculated structures and Mullikan charges of the methyl azide adduct to NbMes (left) and the corresponding imino complex MeN=NbMe3 (right)...

In 2008 Ai published a study (Ai et al. 2008) on tautomer equilibrium of adenine in the presence of Zn cation at the DPT level (B3LYP/6-311+G ). It was foimd that the [Zn-(Ade-N6,N7)] imino complex is the most stable structure in accord with the gas phase calculations of Kabelac (Kabelac and Hobza 2006). The latter calculations explored tautomers of all DNA bases in the presence of Na, Mg, and Zn bare cations evaluated at the R1-MP2/TZVPP level of theory. 

Another type of oximes, amino-oxime ligands, has been developed by the condensation of biacetyl monooxime with 2-(aminomethyl)pyridine and 2-(2-aminoethyl)pyridine. This tridendate ligand led to different stereoisomers. The stability of the various possible isomers of cobalt complexes 147 and 148 has been calculated. The minimum strain energy is observed for a w< r-configuration for imino complexes [Co(L )2] and amino complex [Co(L - )(HL )] + (Figure 43). 

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