Quadruple bond electrons (σπδδ*) has an Os–Os triple bond and a staggered geometry. Many other compounds with quadruple bonds between transition metal atoms have been described, often by Cotton and his coworkers. Isoelectronic with the dirhenium compound is the salt K[MoCl] (potassium octachlorodimolybdate). An example of a ditungsten compound with a quadruple bond is ditungsten tetra(hpp). Quadruple bonds between atoms of main group elements are unknown. Molecular orbital theory shows that there are two sets of paired electrons in the sigma system (one bonding, one antibonding), and two sets of paired electrons in a degenerate π-bonding set of orbitals. This adds up
Owned-and-operated television stations in the United States owned KTLA (channel 5) in Los Angeles and WBKB (channel 4, now WBBM-TV on channel 2) in Chicago, owned a share of the network. However, the FCC declared that Paramount controlled DuMont and thus forbade the network and the studio from acquiring any more stations. This was one of the factors that led to DuMont shutting down in August 1956. For much of the era from 1958 to 1986, the major network-owned stations were distributed as follows: ABC, CBS and NBC each owned stations in the top three markets (New York City, Los Angeles and Chicago). Between 1958 and 1965,