We describe the preparation, structural and magnetic characterizations, and electronic structure calculations for a redox-related family of dinitrogen-bridged chromium acetylide complexes containing the [RC2Cr(mu-N-2)CrC2R](n+) (R = Ph-, (Pr3Si-)-Pr-i; n = 0, 1, 2) backbone: [(dmpe)(4)Cr-2(C2Ph)(2)(mu-N-2)] (1), [(dmpe)(4)Cr-2((C2SiPr3)-Pr-i)(2)(mu-N-2)] (2), [(dmpe)(4)Cr-2((C2SiPr3)-Pr-i)(2)(mu-N-2)]BAr4F (3), and [(dmpe)(4)Cr-2((C2SiPr3)-Pr-i)(2)(mu-N-2)](BAr4F)(2) (4). Compounds 3 and 4 are synthesized via chemical oxidation of 2 with [Cp2Co](+) and [Cp*Fe-2](+), respectively. X-ray structural analyses show that the alteration of the formal Cr oxidation states does not appreciably change the Cr-N-N-Cr skeletal structures. Magnetic data collected for 2 and 4 are consistent with high-spin triplet and quintet ground states, respectively. The mixed-valent complex 3 exhibits temperature dependent magnetic behavior consistent with a quartet doublet two-center spin equilibrium. Electronic structure calculations (B3LYP) performed on the full complexes in 2 and 4 suggest that the high-spin states arise from singly occupied orthogonal pi* orbitals coupled with a variable occupation of d delta orbitals. Significant N-N and Cr-N pi-bonding pins the occupation of the it manifold, leading to variable occupation of the d delta space. In contrast, mixed-valent 3 is not well described by a B3LYP hybrid density functional model. A [9,11] CAS-SORCI study on a simplified model of 3 reproduces the observed Hund's rule violation for the S=1/2 ground state and places the lowest quartet 1.45 kcal/mol above the doublet ground state.