Preparation and microwave absorption properties of rod-like iron phthalocyanine with nitrile and nitro groups

• A simple and effective solvent-thermal route.
• A novel rod-like iron phthalocyanine with nitro and nitrile groups was prepared.
• Introducing strong permanent dipole moment into the Pc molecule.
• Endow TnFePc-CN with excellent microwave absorbing properties.

A novel iron phthalocyanine with nitro and nitrile groups (TnFePc-CN) micro–nano-structure was prepared via a simple and effective solvent-thermal route. SEM, FT-IR, UV–vis and DSC indicated that highly polar nitro and nitrile groups were successfully incorporated in phthalocyanine molecule. The strong permanent dipole moment endowed phthalocyanine with excellent microwave absorbing properties. The large microwave absorbing peak of TnFePc-CN arising at 15.8 GHz, originated from polarization relaxation of the polar nitrile groups, and achieved a maximum absorbing value of −9.76 dB at the thickness of 3.7 mm.