Synthesis of Two-Dimensional Analogues of Copolymers by Site-to-Site Transmetalation of Organometallic Monolayer Sheets

Monolayer sheets have gained attention
due to the unique properties
derived from their two-dimensional structure. One of the key challenges
in sheet modification/synthesis is to exchange integral parts while
keeping them intact. We describe site-to-site trans­metalation
of Zn2+ in the netpoints of cm2-sized, metal–organic
sheets by Fe2+, Co2+, and Pb2+. This
novel transformation was done both randomly and at predetermined patterns
defined by photo­lithography to create monolayer sheets composed
of different netpoints. All trans­metalated sheets are mechanically
strong enough to be spanned over 20 × 20 μm2 sized holes. Density functional theory calculations provide both
a model for the molecular structure of an Fe2+-based sheet
and first insights into how trans­metalation proceeds. Such trans­metalated
sheets with random and patterned netpoints can be considered as two-dimensional
analogues of linear copolymers. Their nanoscale synthesis presents
an advance in monolayer/polymer chemistry with applications in fields
such as surface coating, molecular electronics, device fabrication,
imaging, and sensing.