The potentially tridentate Schiff base derivatives H2nap and Hoap were synthesized by the condensation reaction of 4-amino-2,3-dimethyl-1-phenyl-5-pyrazoline (4-aminoantipyrine)with 2-aminobenzaldehyde and salicylaldehyde, respectively. The reaction of H2nap with [ReOBr3(PPh3)2] and cis-[ReO2I(PPh3)2](1) gives rise to the products [Re(nap)Br2(PPh3)]Br (2) and [ReO(OEt)(Hnap)(PPh3)]I (3), respectively. In 2 the ligand nap is coordinated as a tridentate imido-imino-ketone, while in 3 Hnap is bonded as an amido-imino-ketone. The reaction of Hoap with [ReO2I(PPh3)2] affords the product [ReO(OMe)(oap)(PPh3)]I (4). Spectroscopic data and the X-ray crystal structures of compounds 2-4 are reported.

The oxidation of trans-[ReCl3(MeCN)(PPh3)2] by dioxygen in the presence of the potentially tridentate N2O-donor ligand 2-[((2-pyridinylmethyl)amino)methyl]phenol (Hham) in ethanol led to the formation of the hydrogen-bonded oxorhenium(V) dimer [ReOCl2(ham)]2. With the potentially tetradentate N2O2-chelate N,N-bis(2-hydroxybenzyl)-aminomethylpyridine (H2hap), the '4 + 1' complex [ReOCl(hap)] was isolated. Both compounds were characterized by ¹Ή NMR and infrared spectroscopy, and X-ray crystallography.

The reaction of trans-[ReCl3(MeCN)(PPh3)2] with 1-phenyl-1,3-butadione (Hbat), 2,2'-dipyridylamine (dpa), and 1-(2-hydroxy-phenyl)ethanone benzoylhydrazone (Hhaep) under nitrogen led to the respective complexes cis-[ReIII Cl2(bat)(PPh3)2], fac-[ReIII Cl3(dpa)(PPh3)] and cis-[ReV OCl2(meb)(PPh3)] (meb = N'-(propan-2-ylidene)benzohydrazide). All the complexes were characterized by ¹H NMR and infrared spectroscopy, and X-ray crystallography.

A oxidação de 5,6-diamino-1,3-dimetil-2,4-dioxopirimidina (H2ddd) por perrenato (ReO4-) leva à formação de 1,3-dimetilaloxano, que condensa com H2ddd não-oxidado para produzir 1,3,6,8-tetrametilpirimidopteridino-2,4,5,7-tetrona (tppt). A estrutura do tppt consiste de um anel pirazínico central e dois anéis pirimidínicos terminais em posições cis. Os ângulos diedros entre os anéis pirazina e pirimidina são de 1,08° e 1,20°.

The oxidation of 5,6-diamino-1,3-dimethyl-2,4-dioxopyrimidine (H2ddd) by perrhenate (ReO4-) led to the formation of 1,3-dimethylalloxan, which condenses with unoxidized H2ddd to yield the product 1,3,6,8-tetramethylpyrimidopteridine-2,4,5,7-tetrone (tppt). The structure of tppt consists of a central pyrazine ring and two terminal pyrimidine rings in cis positions. The dihedral angles between the pyrazine and pyrimidine rings are 1.08° and 1.20°.