TY - JOUR
T1 - Structural control in the formation of multidecker sandwich anions of plumbocene
T2 - The effects of encapsulating the alkali metal counterions
AU - Beswick, Michael A.
AU - Gornitzka, Heinz
AU - Kärcher, Jörg
AU - Mosquera, Marta E.G.
AU - Palmer, Julie S.
AU - Raithby, Paul R.
AU - Russell, Christopher A.
AU - Stalke, Dietmar
AU - Steiner, Alexander
AU - Wright, Dominic S.
PY - 1999/3/29
Y1 - 1999/3/29
N2 - Addition of CpM (Cp = C5H5; M = Li, Na, K, Cs) to Cp2E (Cp = C5H5; E = Sn, Pb) produces π-anions of general formula [Cp2x+1Ex]-. Multidecker anions (with x > 1) can be prepared for Pb if crown or cryptand ligands coordinate the alkali metal cations. The syntheses and structures of the new complexes [Cp3Sn]-·[Li(12-crown-4)2]+ (2), [Cp2Pb(μ-Cp)Na·(15-crown-5)] (3), [Cp5Pb2]-[K(2,2,2-crypt)]+·THF (4), [Cp2Pb(μ-Cp)Pb(μ-Cp)Cs(18-crown-6)] (5), and [Cp5- Pb2]-[Li(12-crown-4)2]+·2THF (6) are reported. This study, together with that on [Cp9-Pb4]-[Cp5Pb2] -[{Li(12-crown-4)2 +}2] (1), which we have communicated previously, indicates that charge separation and lattice energy considerations subtly control the aggregation of the multidecker Pb(II) anions involved. These factors allow the potential control of the anion homologues formed by changing the solvation sphere of the alkali metal cations. However, as is illustrated by the structures of 1 and 6, which contain the same [Li(12-crown-4)2]+ countercation, in certain cases structural modification can be controlled by the reaction employed.
AB - Addition of CpM (Cp = C5H5; M = Li, Na, K, Cs) to Cp2E (Cp = C5H5; E = Sn, Pb) produces π-anions of general formula [Cp2x+1Ex]-. Multidecker anions (with x > 1) can be prepared for Pb if crown or cryptand ligands coordinate the alkali metal cations. The syntheses and structures of the new complexes [Cp3Sn]-·[Li(12-crown-4)2]+ (2), [Cp2Pb(μ-Cp)Na·(15-crown-5)] (3), [Cp5Pb2]-[K(2,2,2-crypt)]+·THF (4), [Cp2Pb(μ-Cp)Pb(μ-Cp)Cs(18-crown-6)] (5), and [Cp5- Pb2]-[Li(12-crown-4)2]+·2THF (6) are reported. This study, together with that on [Cp9-Pb4]-[Cp5Pb2] -[{Li(12-crown-4)2 +}2] (1), which we have communicated previously, indicates that charge separation and lattice energy considerations subtly control the aggregation of the multidecker Pb(II) anions involved. These factors allow the potential control of the anion homologues formed by changing the solvation sphere of the alkali metal cations. However, as is illustrated by the structures of 1 and 6, which contain the same [Li(12-crown-4)2]+ countercation, in certain cases structural modification can be controlled by the reaction employed.
UR - http://www.scopus.com/inward/record.url?scp=0000338526&partnerID=8YFLogxK
U2 - 10.1021/om980777p
DO - 10.1021/om980777p
M3 - Article
AN - SCOPUS:0000338526
SN - 0276-7333
VL - 18
SP - 1148
EP - 1153
JO - Organometallics
JF - Organometallics
IS - 7
ER -