Amidinate complexes

Mg(THF), when the stoichiometry was 1 2. Monomeric and dimeric amidinate complexes of magnesium have been studied in detail with respect to potential applications of these compounds in the chemical vapor deposition of magnesium-doped Group 13 compound semiconductor films. The reactions and products are summarized in Scheme 16. ... 

Oxidative addition of diphenyldichalcogenides, PhEEPh (E = S, Se) to Ge(II) bis(amidinate) complexes was found to occur rapidly, resulting in formation of the corresponding Ge(IV) bis(phenylchalcogenolato) derivatives as shown in Scheme 45. Diphenylditelluride did not react even at elevated temperatures. 

Interesting new sulfido complexes of tin have been prepared by the reaction of styrene sulfide with the N-alkylated tin(II) amidinate complexes Sn[RC(NCy)2]2 (Cy = cyclohexyl R = Me, Bu ). The products exhibit two very different bonding modes for the sulfido ligands in one case, S = Sn[RC(NCy)2]2/ a terminal Sn = S moiety was found while in the other case the bridging... 

As representative examples for the reactivity of the Cp Ti(amidinate) complexes some reactions with CS2 and COS are shown in Scheme 88. Other reagents that have been investigated in this study include carbodiimides, isocyanates, CO2, PhNO as well as aldehydes, ketones, and imines. ... 

The role of steric influences on the formation of various vanadium amidinate complexes in the oxidation states +2 and +3 has been studied in detail. The reaction of VCl2(TMEDA)2 and of VCl3(THF)3 with 2 equivalents of formamidinate salts afforded dimeric V2[HC(NCy)2l4 (cf. Section IV.E) with a very short V-V multiple bond and [ [HC(NCy)2 V(/i-Cl)l2 which is also dimeric (Scheme 107). The formation of V2[HC(NCy)2l4 was shown to proceed through the intermediate monomeric [HC(NCy)2l2V(TMEDA), which was isolated and fully characterized. The dinuclear structure was reversibly cleaved by treatment with pyridine forming the monomeric [HC(NCy)2l2V(py)2. ... 

Metathetical reactions between NbCl4(THF)2, NbCls, TaCls, [(Et2N)2TaCl3]2, or (R2N)3Ta(=NBu (R = Me, Et) with various amounts of lithium amidinates have been employed to synthesize the corresponding heteroleptic niobium and tantalum amidinate complexes. The products were investigated as potential precursors to metal nitrides (cf. Section VI) Carbodiimide insertion routes... 

Treatment of bis(pyridine) complexes of molybdenum and tungsten, M(f/ -allyl)Cl(CO)2(py)2 (M = Mo, W) with equimolar amounts of lithium amidinates Li[RC(NPh)2] (R = H, Me) afforded amidinato complexes of the type M(r -allyl)[RC(NPh)2](CO)2(py) (M = Mo, W). Reactions of the latter with acetonitrile, PEts, and P(OMe)3 have been investigated Free amidines react with M(r -allyl)Cl(CO)2(NCMe)2 according to Scheme 124 to give the corresponding bis(amidine) complexes. ... 

Treatment of the bis(amidine) derivatives with a strong base such as Bu Li leads to conversion to the corresponding amidinato(amidine) complexes which on further reaction with triethylphosphine loose the coordinated free amidine as illustrated in Scheme 125. ... 

A unique pair of stereoisomeric dimolybdenum amidinate complexes has been prepared and structurally characterized. The reaction of Li[PhC(NSiMe3)2] with dimolybdenum tetraacetate afforded trans- and ds-Mo2(02CMe)2[PhC (NSiMe3)2]2- While the acetates coordinate to the M02 core via a bridging mode in both compounds, the benzamidinates are bridging in the trans complex and... 

Novel ruthenium-amidinate complexes of the type (j -CgHsRlRufamidina-te)X (R = Me, OMe, F X = Cl, Br, OTf) and [Ru(amidinate)(MeCN)4][PF6] have been synthesized by photochemical displacement of the benzene ligand in (j -CgHglRufamidinatelX by substituted arenes or MeCN. The acetonitrile ligands of [Ru(amidinate)(MeCN)4][PF6] are easily replaceable by other cr-donor ligands (L) such as pyridines, phosphines, and isocyanides to afford the corresponding derivatives [Ru(amidinate)(MeCN) (L)4 ][PF6] n — 1, 2). These reactions are summarized in Scheme 142. ... 

Chlorination of the Cp Ru(amidinate) complexes is readily achieved by treatment with CHCI3, while oxidative addition of allylic halides results in formation of cationic Ti-allyl ruthenium(IV) species (Scheme 243). °... 

In this case the use of the Sm(II) "ate" complex Na[Sm N(SiMe3)2 3] as starting material afforded yet another novel C-substituted amidinate complex resulting from y C-H activation of a N(SiMe3)2 ligand (Scheme 194). All new... 

Bis(amidinate) ligands derived from bulky terphenyl systems were prepared and used for the preparation of dialkylaluminum bis(amidinate) complexes In a... 

In 1994 a remarkable new type of amidinate complex having a strongly M-M bonded Fe core bridged by three N,N -diphenylformamidinato anions was... 

Certain aspects of catalytic applications of transition metal amidinate complexes have already been summarized in review articles. The "Chemistry of... 

In 2007, Smolensky and Eisen published a review entitled "Design of organometallic group IV heteroallylic complexes and their catalytic properties for polymerizations and olefin centered transformations.In this article a strong emphasis was placed on various synthetic and catalytic aspects of group IV metal amidinate complexes. It was clearly pointed out that such amidinate... 

The polymerization of methyl methacrylate (MMA) by Cu(ll) amidinate complexes (Scheme 222) in combination with alkyl aluminum complexes has been reported. The preferred alkylating agent is methylalumoxane (MAO) in... 

Amidinate complexes of copper(I) and copper(II) have been found to catalyze the polymerization of carbodiimides. The copper catalysts are highly active even under air and oxygen. It was shown that the catalytic activity of an air-stable copper(II) amidinato complex is almost equal to that of reported air-sensitive titanium(IV) amidinate initiators. Scheme 225 illustrates the proposed reaction mechanism. ... 

Several patents dealing with the use of volatile metal amidinate complexes in MOCVD or ALD processes have appeared in the literature.The use of volatile amidinato complexes of Al, Ga, and In in the chemical vapor deposition of the respective nitrides has been reported. For example, [PhC(NPh)2]2GaMe was prepared in 68% yield from GaMes and N,N -diphenylbenzamidine in toluene. Various samples of this and related complexes could be heated to 600 °C in N2 to give GaN. A series of homoleptic metal amidinates of the general type [MIRCfNROilnl (R = Me, Bu R = Pr, BuO has been prepared for the transition metals Ti, V, Mn, Fe, Co, Ni, Cu, Ag, and La. The types of products are summarized in Scheme 226. The new compounds were found to have properties well-suited for use as precursors for atomic layer deposition (ALD) of thin films. 

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