Metalloceneincorporated Hybrid Singly N-Methyl N-Confused Calixphyrins: Synthesis, Characterization, Protonation and Deprotonation Studies

Rational design and isolation of two hitherto
unknown highly stable single conformer of ferrocene in-
corporated meso-aryl substituted singly N-methyl N-con-
fused-calixphyrins have been achieved in quantitative yields.
The solid-state crystal structure reveals the obvious trans-
geometry for the meso-protons with the possibility for both
the macrocycles to exist either racemic or enantiomer forms.
However, thorough solution-state spectroscopic character-
ization strongly concludes the experimental isolation of a
single isomer for both the macrocycles. The drastic modifica-
tion of UV-vis spectral patterns upon imine pyrrole N
protonation and amine pyrrole NH deprotonation of both the
calixphyrins could pave way for these macrocycles to act as
opto-electronic materials. The conformational preorganiza-
tion and protonation and deprotonation induced conforma-
tional reorganization have been extensively studied by
solution state spectroscopic techniques, solid state X-ray
crystal structure and in depth DFT level theoretical calcu-
lations.