The trinuclear complexes [{Mo(O)(Tp*)Cl}(mu-1,n-C6H4O2){Mo(O)(Tp*)}(mu-1,n-C6H4O2){Mo(O)(Tp*)Cl}] (1, n = 4; 2, n = 3) have been prepared [Tp* = tris(3,5-dimethylpyrazolyl)hydroborate], in which a chain of three paramagnetic oxo-Mo(V) fragments are linked by two 1,4-[OC6H4O](2-) (for 1) or 1,3-[OC6H4O]2- (for 2) bridging ligands. The crystal structure of 1 .(CH2Cl2)(3.5).(C6H14)(0.5) was determined : C63.5H88B3Cl9Mo3N18O7; triclinic, P (1) over bar; a = 12.052(2) Angstrom, b = 18.487(4) Angstrom, c = 21.039(5) Angstrom; alpha = 68.95(2)degrees, beta = 86.12(2)degrees, gamma =78.637(13)degrees; V= 4289(2) Angstrom(3); Z = 2. It shows a V-shaped Mo-L-Mo-L-Mo array of three {(Tp*)Mo(O)} fragments with two 1,4-[OC6H4O](2-) bridging ligands. The V-shape arises from the cis arrangement of the two bridging ligands at the central metal atom. Electrochemical measurements show the expected Mo(IV)/Mo(V) and Mo(V)/Mo(VI) couples at potentials consistent with significant electrochemical interactions between the terminal and central metal fragments but not between the two terminal metal fragments. Variable-temperature magnetic susceptibility measurements (1.17-225 K) show the occurrence of intramolecular antiferromagnetic (1) and ferromagnetic (2) exchange interactions between adjacent metal atoms with J = -44.0 (1) and +4.5 cm(-1) (2) [based on H = -J(S1S2 + S1S3)] leading to S = 1/2 (1) and 3/2 (2) ground states. These results are in accord with the spin-polarization principle, which predicts that [1,4-C6H4O2](2-) should be an antiferromagnetic linker whereas [1,3-C6H4O2](2-) should be a ferromagnetic linker.