Synthesis and Spectroscopy of Coordination Compounds of a Versatile Bridging Ligand. Molecular Structures of the Dinuclear Compounds [Co2(bdnol)(NCS)3], [Zn2(bdnol)Cl(NCS)2], and [Cu2(bdnol)(NO3)3] and of the Polymeric Copper(I) Compound [Cu2(Hbdnol)(NCS)2]