The title phase was synthesized by direct fusion of a stoichiometric amount of the elements followed by annealing at 650 degreesC for 3 weeks. The compound crystallizes in the orthorhombic space group Pnma (No. 62), Z = 4, with a = 19.451(6) Angstrom, b = 12.164(3) Angstrom, c = 6.581(1) Angstrom. The compound is made up of As3Pb35- crown clusters that can be likened geometrically and electronically to 6-atom hypho-clusters derived from a tricapped trigonal prismatic closo parent. These crowns are interconnected via intercluster Pb-Pb bonds to form infinite chains along the b axis, which means the compound contains an extra two cations and two electrons per formula unit. Extended Huckel calculations indicate that the two additional electrons per cluster are accommodated in pi* states on the cluster and predict that the phase should be semiconducting. The latter is confirmed by microwave resistivity measurements, rho(298) = 1.0 X 10(2) muOmega.cm; (deltarho/deltaT)/rho = -0.14(3) K-1.