In chemistry and materials science, linear chain compounds are materials composed of one-dimensional arrays of metal-metal bonded molecules or ions. Such materials exhibit anisotropic electrical conductivity.
Many linear chain compounds feature square planar complexes. One example is , which stack with distances of about 326 pm. Classic examples include Krogmann's salt and Magnus's green salt. Another example is the partially oxidized derivatives of . The otherwise ordinary complex gives an electrically conductive derivative upon oxidation, e.g., with bromine to give , where x ~0.05. Related chlorides have the formulae and .
In contrast to linear chain compounds, extended metal atom chains (EMACs) are molecules or ions that consist of a finite, often short, linear strings of metal atoms, surrounded by organic ligands.
One group of platinum chains is based on alternating cations and anions of (R = iPr, , ) and . These may be able to be used as vapochromic sensor materials, or materials which change color when exposed to different vapors.
Linear chains of Pd-Pd bonds protected by a "ÃÂ-electron sheath" are known.
Not only do these olefin-stabilized metal chains constitute a significant contribution to the field of organometallic chemistry, both the complex's metal atom structures and the olefin ligands themselves can conduct a current.
Some linear chain compounds are produced or fabricated by electrocrystallization. The technique is used to obtain single crystals of low-dimensional electrical conductors.