The synthesis, X-ray crystal structure, and magnetic studies of a rare example of organic/inorganic spin hybrid clusters extended in infinite ladder-type chain [Cu(C5F6HO2)(2)](7)(C35H35N5O4)(2)([Cu(hfac)(2)](7)(pyacbisNN)(2), 2) formed by the reaction of a high spin nitronylnitroxide biradical C35H35N5O4 (pyacbisNN, 1) and bis(hexafluroacetylacetonate)copper(II) = Cu(hfac)(2) are described. Single-crystal X-ray structure analysis revealed the triclinic P (1) over bar space group of 2 with the following parameters: a = 10.6191(4) angstrom, b = 19.6384(7) angstrom, c = 21.941(9) angstrom, alpha = 107.111(7)degrees, beta = 95.107(8)degrees, gamma = 94.208(0)degrees, Z = 2. Each repeating unit in 2 carries a centrosymmetric cyclic six spin and a linear five spin cluster with four different copper coordination environments having octahedral and square planar geometries. These clusters are interconnected to form infinite chains which are running along the crystallographic b axis. The magnetic measurements show nearly paramagnetic behavior with very small variations over a large temperature range. The magnetic properties are thus result of complex competitions of many weak ferro- and antiferromagnetic interactions, which appear as small deviations from quite linear mu(eff) vs T dependence at low temperature. At high temperature (300-14 K), antiferromagnetic behavior dominates a little, while at very low temperature (14-2 K), a small increase of mu(eff) was observed. The magnetic susceptibility data are described by the Curie-Weiss law [chi = C/(T-theta)] with the optimal parameters C = 4.32 +/- 0.01 emuK/mol and theta = -0.6 +/- 0.3 K, where C is the Curie constant and theta is the Weiss temperature.