A Stable Compound Containing a Silicon-Silicon Triple Bond

• Published in: Science (American Association for the Advancement of Science) Vol. 305; no. 5691; pp. 1755 - 1757
• Main Authors: Sekiguchi, Akira, Kinjo, Rei, Ichinohe, Masaaki
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Association for the Advancement of Science 17.09.2004; Amer Assoc Advancement Science; The American Association for the Advancement of Science
• Subjects: Alkenes; Alkynes; Atoms; Bond angles; Chemical bonds; Chemical compounds; Chemical reactions; Chemical synthesis; Chemistry; Crystals; Emeralds; Exact sciences and technology; Geometry; Graphite; Hexanes; Molecular Structure; Multidisciplinary Sciences; Nuclear magnetic resonance; Observations; Olefins; Organic Chemistry; Organometalloidal and organometallic compounds; Potassium; Preparations and properties; Properties; Protons; Science & Technology; Science & Technology - Other Topics; Si derivatives; Silicon; Structure; Tetrahydrofuran; Japan; CHEMISTRY; ORGANOSILICON COMPOUNDS; Unsaturated compound; Molecular structure; Silicon Organic compounds; Density functional method; Triple bond; Chemical synthesis; Modeling; Ultraviolet visible spectrometry
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1102209

The reaction of 2,2,3,3-tetrabromo-1,1,4,4-tetrakis[bis (trimethylsily)methyl]-1,4-diisopropyltetrasilane with four equivalents of potassium graphite ($KC_8$) in tetrahydrofuran produces 1,1,4,4-tetrakis[bis(trimethylsilyl) methyl]-1,4-diisopropyl-2-tetrasilyne, a stable compound with a silicon-silicon triple bond, which can be isolated as emerald green crystals stable up to$100\textdegree C$in the absence of air. The$Si\equiv Si$triple-bond length (and its estimated standard deviation) is 2.0622(9) angstroms, which shows half the magnitude of the bond shortening of alkynes compared with that of alkenes. Unlike alkynes, the substituents at the$Si\equiv Si$group are not arranged in a linear fashion, but are trans-bent with a bond angle of$137.44(4)\textdegree$.