In attempts to generate complexes containing both nitroxyl and nitroxide ligands (TEMPO (0/−) or ABNO (0/−) ), metathetical methods were employed with MnBr 2 (THF) 2 and various iron halides. While η 2 - and η 1 -TEMPO (or ABNO) were found to be the dominant binding motifs, deoxygenation proved to be a common path. A successful synthesis of (η 2 -μ-O, N-TEMPO) 2 Na 2 Mn (1) was realized, and the structure of (η 2 -μ-O, N-TEMPO) 2 Na (TEMPO) (TEMPO) 2 Fe (2) can be rationalized as having a nitroxyl bound to Na cation, in an Fe (III) complex whose total spin of S = 2 reflects an S = 5/2 core antiferromagnetically coupled to the nitroxyl. In one instance, the products of deoxygenation were contained in a diiron product, (TMP) (TEMPO) 5 (μ-O) Fe 2 Li 2 (5, TMP = tetramethylpiperidide). In other cases, unprecedented aggregates formed as tentative formulations suggest they contain “ (TMP) 6 Fe (μ 3 -O) 6 ” (3) and “ (TEMPO) 2 Na 4 Fe 6 (μ 3 -O) 4 (μ 4 -O) 2 (TEMPO) 2 }” (4). Na (ABNO) 6 (THF) 4 (NaABNO) was crystallographically characterized as a pseudo hexamer of stacked cubes. Metathetic utilization of NaABNO afforded (ABNO) 6 (μ-O) Fe 2 Na 2 (7), and the ABN (9-azyl-bicyclo3. 3. 1nonane) unit coproduced was tentatively identified in the byproduct (η 2 -ABNO) 2 (ABNO) (ABN) Fe (6). While the goal of homoleptic nitroxyl/nitroxide complexes was unrealized, clearly these reagents are effective means of producing oxidic aggregates. • Near homoleptic nitroxyl complexes. • Na (ABNO) 6 (THF) 4, a pseudo hexamer of stacked cubes. • Deoxgenation products. • Unique hexairon (III) clusters.
Kayser et al. (Tue,) studied this question.