1. The Molecular Foundry, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, Department of Chemistry, University of California, Berkeley, California 94720, Dipartimento di Chimica “G. Ciamician”, Università degli Studi di Bologna, via Selmi 2, 40126 Bologna, Italy, and Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095