Abstract
Nitrous oxide (N(2)O) is sometimes referred to as the forgotten greenhouse gas, but ignoring it would be a mistake. N(2)O has a greenhouse warming potential 300× that of CO(2), and anthropogenic emissions are increasing. Yet, compared to CO(2), homogeneous catalysts that mediate its reduction are scarce. We present a range of cluster catalysts based on abundant and inexpensive p-block elements that mediate the conversion of N(2)O to environmentally benign N(2). The catalysts studied offer many critical advantages, and systems can be tuned for performance, recyclability, selectivity, air stability, and commercial availability. Pnictogen clusters present themselves as a general platform in N(2)O reduction chemistry, and control reactions confirm that these clusters offer access to reactivity that simple monopnictogen molecules do not. Mechanistic investigations reveal that the low-valent clusters can access a -1/+1 redox couple, which goes beyond classical main group redox couples and will unlock a vault of hitherto unknown chemical space.