Ethane dication

The preferred structure of the diprotonated C2H82+ ethane dication (452) considered theoretically786 incorporates two pentacoordinate carbons and an unprotonated C C bond (HF/6-31G level). A new calculation by Olah et al.788 (MP2/6-31G ) has... 

Bis(diisopropylamino)triafulvene (7) yields an iron carbonyl complex upon reaction with cyclopentadicnyl(dicarbonyl)iron iodide and l,2-bis(2,3-diisopropylaminocyclopropenylium)-ethane dication by coupling upon oxidation with iodine. 

The cw-dibenzo-24-crown-8- and his(meta-phenylene)-32-crown-10-based capsules 227 and 252 (see Sect. 2.3.1) are described in [177] to form host-guest 1 1 and 2 1 cage complexes (Scheme 2.156), respectively, with an encapsulated A -methylated l,2-bis-(4-pyridinium)ethane dication. In them, the Af-methyl group of this... 

Bianchini et al 1 have obtained triphos-capped tetrathio- and tetraseleno-oxalate bridged Rh dimer dications of the structure (triphos)Rh(C2E4)Rh(triphos)3, where triphos = 1,1,1-tris-(diphenylphosphinomethyl)ethane and E = S, Se. 

Examples are the 1, l -dibenzyl-4, 4 -bipyridinium electron-acceptor dication threaded into the 1, 5-dinaphtho-38-crown-10 (Fig. 2a) [10], and the acyclic polyether containing a dioxybenzene electron-donor unit threaded into the electron-acceptor cyclobis(paraquat-p-phenylene) tetracationic cyclophane (Fig. 2b) [11]. Although in these cases a large contribution to the association driving force comes from the electron-donor/acceptor (charge-transfer, CT) interactions, hydrogen bonding can also play an important role, as clearly shown in the cases of pseudorotaxanes constituted by 4, 4 -bipyridinium [12a] or l,2-bis(pyridinium)ethane [12b] threads and crown ethers. 

The reactivity of doubly charged rare earth cations with small hydrocarbons was also investigated by FTICR-MS. In early studies, Freiser and coworkers examined reactions of Sc and Y " " (Hill et al., 1997), as well as La (Ranasinghe et al., 1992), with linear Cj-Cg alkanes combinations of electron transfer, hydride transfer, carbanion transfer, dehydrogenation, and alkane-loss products were observed. None of the metal ions reacted with methane, and La + was also unreactive with ethane. Since the metal dications have only one valence electron, oxidative addition to form two covalent bonds to the metal center is not possible, and alternative multicentered mechanisms were proposed. Another interesting aspect of these studies was the observation... 

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