ELECTROSYNTHESIS AND ELECTRODOPING OF C-60(N-) (N = 0, 1, 2, OR 3) FILMS - ELECTROCHEMICAL QUARTZ-CRYSTAL MICROBALANCE STUDY IN ACETONITRILE SOLUTIONS OF ALKALI-METAL, ALKALINE-EARTH-METAL, AND TETRA-N-BUTYLAMMONIUM CATIONS
Wy. Koh et al., ELECTROSYNTHESIS AND ELECTRODOPING OF C-60(N-) (N = 0, 1, 2, OR 3) FILMS - ELECTROCHEMICAL QUARTZ-CRYSTAL MICROBALANCE STUDY IN ACETONITRILE SOLUTIONS OF ALKALI-METAL, ALKALINE-EARTH-METAL, AND TETRA-N-BUTYLAMMONIUM CATIONS, Journal of physical chemistry, 97(26), 1993, pp. 6871-6879
The electrosynthesis, electrodoping/undoping, and electrodissolution o
f thin films of C60 and its salts were studied in acetonitrile solutio
ns at a Au/quartz electrode by simultaneous electrochemistry and micro
gravimetry with an electrochemical quartz crystal microbalance. The C-
60(0) films were deposited either by electrooxidation of C-60(2-) in s
olutions containing CsAsF6, KPF6, or Ca(PF6)2, or by electrooxidation
of C-60(3-) in solutions containing tetra-n-butylammonium perchlorate,
(TBA)ClO4. The initial C-60(2-) or C-60(3-) anions were prepared by c
ontrolled-potential bulk electroreduction of a C-66(0) suspension. The
C-60(0) films electrodeposited from a C-60(2-) solution containing Cs
+, K+, or Ca2+ cations could not be electrodoped with these cations bu
t a conductive (Cs+)3(C60(3-)) film could be quantitatively electrosyn
thesized by electroreduction of C60(2-) in a solution containing Cs+.
Attempts to electrodeposit (K+)3(C60(3-)) or (Ca2+)3(C60(3-))2 films w
ere unsuccessful but a (Ca2+)(C60-)2 film could be prepared. The compo
sition of a given C-60(0) film electrodeposited by constant potential
electrooxidation of C-60(3-) in an acetonitrile solution containing (T
BA)ClO4 was controlled by the initial C-60(3-) concentration and/or th
e electrodeposition potential. These C-60(0) films could be electrodop
ed with TBA+ cations from solution upon electroreduction at appropriat
e potentials and both (TBA+)(C60-) and (TBA+)2(C60(2-)) films were obt
ained. Films of the same composition could also be obtained by electro
oxidation of concentrated C-60(3-) solutions containing (TBA)ClO4 at a
suitably selected potential.