Amide-Templated Iodoplumbates: Extending Lead-Iodide Based Hybrid Semiconductors

Lead iodide–organic hybrids
(iodoplumbates) have emerged
as a class of materials with promising electronic and optical properties,
and potential applications in photovoltaics and electronic devices.
Hybrid iodoplumbates are composed of organic cations and lead iodide
anions that exhibit diverse morphologies which determine the optical
and electronic properties of the crystal. However, the diversity of
the iodoplumbates is limited by the types of organic cations amenable
for integration into the structure. Amides represent one of the largest
groups of organic molecules, yet no examples of iodoplumbates based
on protonated amide cations have been demonstrated so far. In this
work, we show that it is possible to consistently grow iodoplumbates
from amides following two distinct pathways. The first pathway involves
growing iodoplumbates using amidium (protonated amides) as the organic
cation in the crystal, which occurs for tertiary amides and urea.
The second pathway involves growing iodoplumbates from primary and
secondary amides, resulting in crystals containing the ammonium hydrolysis
product of the amide. This path also leads to an interesting case
of ring opening crystallization. The lead iodide one-dimensional chain
motif composes most of the resulting structures. The large number
of available amide molecules suggests that this method considerably
expands the range of possible iodoplumbate structures.