Ir(tpy)(bpy)Cl as a Photocatalyst for CO2 Reduction under Visible-Light Irradiation

Abstract

Summary

A photochemical reduction of CO₂ to formic acid was shown using the iridium complex [Ir(bpy)(tpy)Cl][PF6]2. Turnover numbers (TONs) of 20 for formic acid were obtained in acetonitrile. The experiments were conducted under visible-light irradiation (λ > 410 nm) using TEOA as sacrificial reductant (see section SEDs below).

Additional remarks

Upon irradiation, the photocatalyst [Ir(bpy)(tpy)Cl][PF6]2 underwent a structural change to [Ir(piperidine-2,6-di-2-pyridine)(bpy)H]₂⁺ 100869. This reduction was found to induce the HCOOH production.

Content of the published article in detail

Catalyst/Photosensitizer

[Ir(bpy)(tpy)Cl][PF6]2 [Ir(dmbpy)(tpy)Cl][PF6]2 [Ir(dnbpy)(tpy)Cl][PF6]2 100869

Investigation

	cat	cat conc [µM]	e-D	solvent A	.	.	.	λexc [nm]	.	TON CO	TON H2	TON HCOOH	.
1.	[Ir(bpy)(tpy)Cl][PF6]2	0.1	TEOA	MeCN				410 - 750 nm		2	1	20
2.	[Ir(dmbpy)(tpy)Cl][PF6]2	0.1	TEOA	MeCN				410 - 750 nm		5	3	9
3.	[Ir(dnbpy)(tpy)Cl][PF6]2	0.1	TEOA	MeCN				410 - 750 nm		3	1	5
4.	Molecule:100869	0.1	TEOA	MeCN				410 - 750 nm		0	1	7

Experiment-Name: Photoreduction of CO2Export

Sacrificial electron donor

In this study, the experiments were done with the sacrificial reductant TEOA (TEOA).

Additives

In this study, no additives were tested.