Quadruple bond Quadruple bond A quadruple bond is a type of chemical bond between two atoms involving eight electrons. This bond is an extension of the more familiar types double bonds and triple bonds. Stable quadruple bonds are most common among the transition metals in the middle of the d-block, such as rhenium, tungsten, molybdenum and chromium. Typically the ligands that support quadruple bonds are π-donors, not π-acceptors. Chromium(II) acetate, Cr("μ"-OCCH)(HO), was the first chemical compound containing a quadruple bond to be synthesized. It was described in 1844 by E. Peligot, although its distinctive bonding was not recognized for more than a
Owned-and-operated television stations in the United States and CBS' KMOX-TV (channel 4, now KMOV) in St. Louis. As a result of a revision to the FCC's media ownership rules in 1999, a company can now own any number of television stations with a combined market reach of less than 39% of the country, but cannot own two of the four highest-rated stations in any market. Still, O&Os in the United States are primarily found in large markets such as New York City, Los Angeles and Chicago, among others. Despite that, network-owned stations can still be found in smaller markets (for example, KFSN-TV (channel 30) in Fresno, California