Synthesis of a Metallamacrocyclic Re(CO)₃ Complex Using a Tridentate Bridging Ligand

The reaction of [ReBr 3 (CO) 3 ][NEt 4 ] 2 with 3‐hydroxy‐1,2,3‐benzotriazine‐4(3 H )‐one in the presence of base gave the ionic rhenium complex [ReBr(C 7 H 4 N 3 O 2 )(CO) 3 ][NEt 4 ] ( 2 ) which was crystallographically characterized. A neutral metallamacrocycle 3 was obtained upon abstraction of [NEt 4 ]Br from complex 2 . This complex cocrystallizes with an unusual C 3 ‐symmetric [Ag(η 2 ‐benzene) 3 (OH 2 )][BF 4 ] complex as evidenced by single‐crystal X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)