Treatment of {[}M-2(-Cl)(2)(cod)(2)] (M=Ir and Rh) with Na{[}H2B(bt)(2)] (cod=1,5-cyclooctadiene and bt=2-mercaptobenzothiazolyl) at low temperature led to the formation of dimetallaheterocycles {[}(Mcod)(2)(bt)(2)], 1 and 2 (1: M=Ir and 2: M=Rh) and a borate complex {[}Rh(cod)\{(2)-S,S-H2B(bt)(2)\}], 3. Compounds 1 and 2 are structurally characterized metal analogues of 1,5-cyclooctadiene. Metal-metal bond distances of 3.6195(9)angstrom in 1 and 3.6749(9)angstrom in 2 are too long to consider as bonding. In an attempt to generate the Ru analogue of 1 and 2, that is {[}(Rucod)(2)(bt)(2)], we have carried out the reaction of {[}Ru(Cl)(2)(cod)(CH3CN)(2)] with Na{[}H2B(bt)(2)]. Interestingly, the reaction yielded agostic complexes {[}Ru(cod)L\{(3)-H,S,S-H2B(bt)(2)\}], 4 and 5 (4: L=Cl; 5: L=C7H4NS2). One of the key differences between 4 and 5 is the presence of different ancillary ligands at the metal center. The natural bond orbital (NBO) analysis of 1 and 2 shows that there is four lone pairs of electrons on each metal center with a significant amount of d character. Furthermore, the electronic structures and the bonding of these complexes have been established on the ground of quantum-chemical calculations. All of the new compounds were characterized by IR, H-1, B-11, (CNMR)-C-13 spectroscopy, and X-ray crystallographic analysis.