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
Double (volleyball) and indicates outstanding all-around individual performance. Quadruple-double is defined as an individual performance in which a player accumulates a double digit number total in four of the five major statistical categories--aces, kills, blocks, digs, and assists--during the course of one match. Because of specialization by position (setters, liberos, middle blockers, outside hitters, opposite hitters, defensive specialists, etc.), quadruple doubles are seldom seen at collegiate or professional levels. Quintuple-double is defined as an individual performance in which a player accumulates a double digit number total in all five statistical categories (aces, kills, blocks, digs, and assists) in a single match. Such