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 fourth-ranked Philadelphia housed CBS-owned WCAU-TV (channel 10) and NBC-owned WRCV-TV (channel 3, now KYW-TV), a station which NBC had acquired two years earlier through a trade with Westinghouse Broadcasting in return for NBC's television and radio stations in Cleveland. The FCC reversed the trade in 1965 and NBC regained control of the Cleveland television station, which is today known as WKYC. Each network owned stations in other markets where the other networks did not: in addition to Cleveland, these were ABC's KGO-TV (channel 7) in San Francisco and WXYZ-TV (channel 7) in Detroit, NBC's WRC-TV (channel 4) in Washington, D.C.,