A compound having formula (Ph
3
C)
m
Ar(R
1
)
j
(OR
2
)
n
, wherein Ph represents a phenyl group, Ar is an aromatic ring system having from six to twenty carbon atoms, R
1
and R
2
independently are C
1
-C
18
alkyl or C
4
-C
18
heteroalkyl, m is one or two, j is an integer from one to four and n is an integer from one to three.
A compound having formula (Ph3C)mAr(R1)j(OR2)n, wherein Ph represents a phenyl group, Ar is an aromatic ring system having from six to twenty carbon atoms, R1 and R2 independently are C1-C18 alkyl or C4-C18 heteroalkyl, m is one or two, j is an integer from one to four and n is an integer from one to three.
A compound having formula (Ph3C)mAr(R1)j(OR2)n, wherein Ph represents a phenyl group, Ar is an aromatic ring system having from six to twenty carbon atoms, R1 and R2 independently are C1-C18 alkyl or C4-C18 heteroalkyl, m is one or two, j is an integer from one to four and n is an integer from one to three.