From metal carbonyls

Many arene metal tricarbonyl complexes where the metal is chromium, molybdenum or tungsten have been prepared by this route although the [Pg.169]

Rate studies on the reaction between arenes and Mo(CO) show the reaction to be first order with respect to the carbonyl. This is consistent with the proposed inversion mechanism, shown below [46]. [Pg.170]

A stepwise mechanism similar to that proposed for arene displacement reactions (see p. 178) cannot be eliminated. [Pg.170]

In some cases, in the reaction between metal carbonyls and the arene ligand, it is necessary to use aluminium trihalides as a catalyst, e.g. [Pg.170]

Amongst the many substituted benzenes which form the stable complexes, areneM(CO)3, are condensed aromatic hydrocarbons, such as naphthalene, phenanthrene, acenaphthylene, pyrene, chrysene, indene and fluorene [49, 50, 51, 52, 53]. [Pg.170]

METHODS OF PREPARATION OF CARBENE COMPLEXES - a. From metal carbonyls [Pg.292]

The most general method of synthesis of carbene complexes is the action of nucleophiles on coordinated carbon monoxide leading to acyl derivatives followed by their alkylation. In this way, Fischer synthesized the first carbene complex. [Pg.292]

In addition to diazomethane and trialkyloxonium salts, methyl fluorosulfonate, Me0S02F, may be used as an alkylating agent. Similarly, instead of LiR, many other nucleophilic lithium compounds may be utilized. [Pg.292]

This type of reaction may also involve the action of anionic carbonyl complexes on metal alkyl compounds [Pg.292]

In view of the excellent donor properties of tertiary arsines, it is of interest to inquire whether these cyc/o-polyarsanes can also act as ligands. Indeed, (MeAs)s can displace CO from metal carbonyls to form complexes in which it behaves as a uni-, bi- or triden-tate ligand. For example, direct reaction of (MeAs)5 with M(CO)6 in benzene at 170° (M = Cr, Mo, W) yielded red crystalline compounds [M(CO)3( -As5Me5)] for which the structure... [Pg.585]

From Metal Carbonyls to Ziegler-Natta Catalysts... [Pg.117]

Metal clusters on supports are typically synthesized from organometallic precursors and often from metal carbonyls, as follows (1) The precursor metal cluster may be deposited onto a support surface from solution or (2) a mononuclear metal complex may react with the support to form an adsorbed metal complex that is treated to convert it into an adsorbed metal carbonyl cluster or (3) a mononuclear metal complex precursor may react with the support in a single reaction to form a metal carbonyl cluster bonded to the support. In a subsequent synthesis step, metal carbonyl clusters on a support may be treated to remove the carbonyl ligands, because these occupy bonding positions that limit the catalytic activity. [Pg.213]

Rigby J, Kondratenkov M (2004) Arene Complexes as Catalysts. 7 181-204 Risse T, Freund H-J (2005) Spectroscopic Characterization of Organometallic Centers on Insulator Single Crystal Surfaces From Metal Carbonyls to Ziegler-Natta Catalysts. 16 117-149... [Pg.286]

Spectroscopic Characterization of Organometallic Centers on Insulator Single Crystal Surfaces From Metal Carbonyls to Ziegler-Natta Catalysts... [Pg.301]

Suslick KS, Flint EB, Grinstaff MW, Kemper KA (1993) Sonoluminescence from metal carbonyls. J Phys Chem 97 3098-3099... [Pg.377]

The induction of steric effects by the pore walls was first demonstrated with heterogeneous catalysts, prepared from metal carbonyl clusters such as Rh6(CO)16, Ru3(CO)12, or Ir4(CO)12, which were synthesized in situ after a cation exchange process under CO in the large pores of zeolites such as HY, NaY, or 13X.25,26 The zeolite-entrapped carbonyl clusters are stable towards oxidation-reduction cycles this is in sharp contrast to the behavior of the same clusters supported on non-porous inorganic oxides. At high temperatures these metal carbonyl clusters aggregate to small metal particles, whose size is restricted by the dimensions of the zeolitic framework. Moreover, for a number of reactions, the size of the pores controls the size of the products formed thus a higher selectivity to the lower hydrocarbons has been reported for the Fischer Tropsch reaction. [Pg.448]

The preparation of quinoline and tetrahydroquinoline derivatives from metal carbonyl-catalyzed reactions of Schiff bases with alkyl vinyl ethers in... [Pg.383]

Table 4.5. Average values (kJ/mol) of the metal—metal bond enthalpies estimated from metal carbonyls (Mco) and from bulk metals (Mmet) (adapted from Mingos and Wales (1990)).

A. Mono- and Binuclear Complexes from Metal Carbonyls 1. Iron... [Pg.199]

Catalysts Prepared from Metal Carbonyls of Croups 6, 7, 10 and Gold 317... [Pg.317]

As was mentioned in Section III,A a very useful method of synthesis of olefin complexes involves the displacement of carbon monoxide from metal carbonyls by olefins. Under similar conditions acetylenes usually react to give new ligands, e.g., cyclobutadienes, cyclopentadienones, and quinones (see Sections V,E and VI,C), and it is not surprising, therefore, that the range of known acetylene complexes is smaller than the range of olefin complexes. [Pg.104]

Elimination of carbon monoxide from metal carbonyls and coordination of the organosilicon olefin has been reported for divinylsilanes (54, 108, 109) (the compounds obtained are air-sensitive) ... [Pg.120]

The ligand-exchange method is the most used method in the synthesis of ji-complexes. The examples of such compounds, obtained from metal carbonyls and cyclic unsaturated hydrocarbons, are represented in a classic issue [11], Among these ligand-exchange syntheses, we mention here the transformations (3.119)—(3.121) ... [Pg.204]

High pure metal powders can be prepared from metal carbonyls. Thus, US irradiation provokes the irreversible destruction of Fe(CO)5 and formation of Fe3(CO)12 836 [Scheme (3.291)] [750] ... [Pg.291]

F. Mixed Cyanocarbonyl Metalates Prepared from Metal Carbonyl Derivatives and NaN(SiMes)2. 38... [Pg.1]

Supported nanoclusters made from metal carbonyl clusters are emphasized here, because there are numerous characterization data on which to base the discussion. The synthetic methods are illustrated by the following examples. [Pg.66]

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