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.[1][2]

Magnus's green salt is an example of a linear chain compound.

Examples

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Many linear chain compounds feature square planar complexes. One example is Rh(acac)(CO)2, which stack with Rh···Rh distances of about 326 pm.[3] Classic examples include Krogmann's salt and Magnus's green salt. Another example is the partially oxidized derivatives of [Pt(oxalate)2]2−. The otherwise ordinary complex IrBr(CO)3 gives an electrically conductive derivative upon oxidation, e.g., with bromine to give IrBr1+x(CO)3−x, where x ~0.05.[2][4] Related chlorides have the formulae IrCl1+x(CO)3 and K0.6Ir(CO)2Cl2·½H2O.[5]

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.[6]

 
An Ni9 EMAC.[7]
 
Portion of the lattice of Dicarbonyl(acetylacetonato)rhodium(I) (Rh(acac)(CO)2) showing the "stacking" of the individual planar units through Rh···Rh interactions.

One group of platinum chains is based on alternating cations and anions of [Pt(CNR)4]2+ (R = iPr, c-C12H23, p-(C2H5)C6H4) and [Pt(CN)4]2−.[1] These may be able to be used as vapochromic sensor materials, or materials which change color when exposed to different vapors.[8][9][10]

Linear chains of Pd-Pd bonds protected by a "π-electron sheath" are known.[1][11]

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.[1][12]

Methodology

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Some linear chain compounds are produced or fabricated by electrocrystallization. The technique is used to obtain single crystals of low-dimensional electrical conductors.[13]

See also

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References

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  1. ^ a b c d Bera, J. K.; Dunbar, K. R. (2002). "Chain Compounds Based on Transition Metal Backbones: New Life for an Old Topic". Angew. Chem. Int. Ed. 41 (23): 4453–4457. doi:10.1002/1521-3773(20021202)41:23<4453::AID-ANIE4453>3.0.CO;2-1. PMID 12458505.
  2. ^ a b Miller, Joel S. (1982). Miller, Joel S (ed.). Extended Linear Chain Compounds. Springer-Verlag. doi:10.1007/978-1-4613-3249-7. ISBN 978-1-4613-3251-0.
  3. ^ Huq, Fazlul; Skapski, Andrzej C. (1974). "Refinement of the crystal structure of acetylacetonatodicarbonylrhodium(I)". J. Cryst. Mol. Struct. 4 (6): 411–418. doi:10.1007/BF01220097. S2CID 96977904.
  4. ^ Tsuji, Yuta; Hoffmann, Roald; Miller, Joel S. (2016). "Revisiting Ir(CO)3Cl". Polyhedron. 103: 141–149. doi:10.1016/j.poly.2015.09.050.
  5. ^ Ginsberg, A. P.; Koepke, J. W.; Sprinkle, C. R. (2007). "Linear-Chain Iridium Carbonyl Halides". Inorganic Syntheses. Vol. 19. pp. 18–22. doi:10.1002/9780470132500.ch5. ISBN 9780470132500.
  6. ^ F. Albert Cotton, Carlos A. Murillo, Richard A. Walton (eds.), Multiple Bonds Between Metal Atoms, 3rd edition, Springer (2005)
  7. ^ Hua, Shao-An; Liu, Isiah Po-Chun; Hasanov, Hasan; Huang, Gin-Chen; Ismayilov, Rayyat Huseyn; Chiu, Chien-Lan; Yeh, Chen-Yu; Lee, Gene-Hsiang; Peng, Shie-Ming (2010). "Probing the electronic communication of linear heptanickel and nonanickel string complexes by utilizing two redox-active [Ni2(napy)4]3+ moieties" (PDF). Dalton Transactions. 39 (16): 3890–6. doi:10.1039/b923125k. PMID 20372713.
  8. ^ Grate, J. W.; Moore, L. K.; Janzen, D. E.; Veltkamp, D. J.; Kaganove, S.; Drew, S. M.; Mann, K. R. (2002). "Steplike Response Behavior of a New Vapochromic Platinum Complex Observed with Simultaneous Acoustic Wave Sensor and Optical Reflectance Measurements". Chem. Mater. 14 (3): 1058–1066. doi:10.1021/cm0104506.
  9. ^ Buss, C.E.; Mann, K.R. (2002). "Synthesis and Characterization of Pt(CN\-p\-(C2H5)C6H4)2(CN)2, a Crystalline Vapoluminescent Compound That Detects Vapor-Phase Aromatic Hydrocarbons". J. Am. Chem. Soc. 124 (6): 1031–1039. doi:10.1021/ja011986v. PMID 11829612.
  10. ^ Buss, C.E.; Anderson, C.E.; Pomije, M. K.; Lutz, C. M.; Britton, D.; Mann, K. R. (1998). "Structural Investigations of Vapochromic Behavior. X-ray Single-Crystal and Powder Diffraction Studies of [Pt(CN\-iso\-C3H7)4][M(CN)4] for M = Pt or Pd". J. Am. Chem. Soc. 120 (31): 7783–7790. doi:10.1021/ja981218c.
  11. ^ Mino, Y; Mochizuki, E; Kai, Y; Kurosawa, H (2001). "Reversible Interconversion between Dinuclear Sandwich and Half-Sandwich Complexes: Unique Dynamic Behavior of a Pd-Pd Moiety Surrounded by an sp2-Carbon Framework". J. Am. Chem. Soc. 123 (28): 6927–6928. doi:10.1021/ja010027y.
  12. ^ Murahashi, T; Nagai, Okuno, T; Matsutani, T; Kurosawa, H. (2000). "Synthesis and ligand substitution reactions of a homoleptic acetonitrile dipalladium(I) complex". Chem. Commun. (17): 1689–1690. doi:10.1039/b004726k.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  13. ^ Williams, Jack M (1989). "Highly Conducting and Superconducting Synthetic Metals". Inorganic Syntheses. Vol. 26. pp. 386–394. doi:10.1002/9780470132579.ch70. ISBN 978-0-470-13257-9.