Molecular structures of the pentaphenylcyclopentadienyl iron complexes [(C5Ph5)Fe(CO)2 R] (R = Me, Ph, iPr and Bu)

The PdII-catalysed reaction of [(C5Ph5)Fe(CO)2Br] with Grignard compounds RMgX or butyl lithium gave the iron alkyl/aryl complexes [(C5Ph5)Fe(CO)2 R] (R = Me, Ph, iPr and Bu) in 59–73% yield, namely, dicarbonylmethyl(η5-pentaphenylcyclopentadienyl)iron, [Fe(CH3)(C35H25)(CO)2], dicarbonyl(η5-pentaphenylcyclopentadienyl)phenyliron, [Fe(C6H5)(C35H25)(CO)2], dicarbonyl(isopropyl)(η5-pentaphenylcyclopentadienyl)iron, [Fe(C3H7)(C35H25)(CO)2], and butyldicarbonyl(η5-pentaphenylcyclopentadienyl)iron, [Fe(C4H9)(C35H25)(CO)2]. The crystal structure determinations showed the usual `paddle-wheel' orientation of the phenyl rings, with an average canting angle of ca 50°. The bond parameters are mainly dictated by the steric requirements of the alkyl/aryl groups and only the phenyl complex shows electronic effects.

Novel Diastereoselective Synthesis of 1-Trimethylgermyl-1-alkenes by Hydrolysis of α-Trimethylgermylzirconacyclopentenes

1-Trimethyl-1-germylalkynes were synthesized by deprotonation of terminal alkynes with n-butyl lithium at low temperature followed by treatment with trimethylgermyl chloride under nitrogen atmosphere. The reagent system Cp2ZrCl2/2EtMgBr converts 1-trimethylgermyl-1-alkynes into α- trimethylgermylzirconacyclopentenes at -78 ºC for 1 h followed by stirring at room temperature overnight. These novel intermediates are hydrolyzed at 0 ºC for an hour to provide the corresponding (Z)-1-trimethylgermyl-1-alkenes in good yields (74-85%) and in high stereochemical purities (> 98%) as evidenced by 13C spectral data.

“Intrinsic” Anion Exchange Polymers through the Dissociation of Strong Basic Groups: PPO with Grafted Bicyclic Guanidines

We synthesized anion exchange polymers by a reaction of chloromethylated poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) with strongly basic 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD). TBD contains secondary and tertiary amine groups in the guanidine portion. To favor the functionalization with the secondary amine, TBD was activated with butyl lithium. The yield of amine formation via the reaction of the benzyl chloride moiety with TBD was 85%. Furthermore, we prepared polymers with quaternary ammonium groups by the reaction of PPO-TBD with CH3I. The synthesis pathways and ionomer structure were investigated by NMR spectroscopy. The thermal decomposition of both ionomers, studied by thermogravimetry, started above 200 °C, corresponding to the loss of the basic group. The ion exchange capacities, water uptake and volumetric swelling are also reported. The “intrinsic” anion conductivity of PPO-TBD due to the dissociation of grafted TBD was in the order of 1 mS/cm (Cl form). The quaternized ionomer (PPO-TBD-Me) showed an even larger ionic conductivity, above 10 mS/cm at 80 °C in fully humidified conditions.

Metalation Studies on Titanocene Dithiolates

Titanocene bis-arylthiolates [(C5H4X)(C5H4Y)Ti(SC6H4R)2] (X,Y = H, Cl; R = H, Me) can be prepared from the corresponding titanocene dichlorides by reacting with the thiols in the presence of DABCO as a base. They react with n-butyl lithium to give unstable Ti(III) radical anions. While the unsubstituted thiolates (X = Y = R = H) react with lithium Di-isopropylamide by decomposing to dimeric fulvalene-bridged and thiolate-bridged Ti(III) compounds, the ring-chlorinated compounds can be deprotonated with LDA and give appropriate electrophiles di-substituted and tri-substituted titanocene dithiolates.

Selective antimony reduction initiating the nucleation and growth of InSb quantum dots

Butyl lithium reduces tris(dimethylamino)antimony to stibine in situ which then reacts with indium-oleate to selectively produce InSb quantum dots.

On the Mechanisms of Chemical Intercalation of Lithium in Electrode Materials

Reaction with n-butyl lithium (BuLi) is commonly used to study the kinetics of intercalation of lithium in electrode materials for batteries. We performed lithium isotope exchange experiments on TiS