Talk:Molecular solid

Inaccuracies

This article is inaccurate. It claims that molecular solids are soft and insoluble in water, and are non-conducting. This is untrue; water itself being the prime example (at low temperatures, ice can be as hard as steel; water self-ionizes and therefore is able to conduct electricity). Liquid sulfuric acid, for example, is extremely soluble in water: so much so that the reaction is dangerously explosive and exothermic. But above all, this article is sorely lacking in references, and reads like it was written in a hurry.—Tetracube (talk) 16:39, 4 May 2010 (UTC)

Rewrote. Conductivity part was correct - liquids don't count here; pure molecular solids are insulators as a rule and heavy doping makes them conducting, but also somewhat ionic. Solubility part was dubious and thus deleted. It hinged on that polar solvents dissolve polar solids and vice versa, which is not a general rule. For example, acetone and water have comparable polarity but are very different solvents. Materialscientist (talk) 07:28, 14 May 2010 (UTC)

Fullerenes

Are fullerenes really molecular solids? I'm not sure about this but I read a fullerene is a single atom so this doesn't seem right to me. CoatThese (talk) 20:39, 31 July 2016 (UTC)

I have found fullerenes to be considered molecular solids by most books on the matter. A fullerene is a molecule consisting of numerous carbons (typically 60 or 70 carbons) covalently bonded in the shape a soccer ball. These soccer balls when brought to a low enough temperature will condense into a solid by van der Waals forces.Cryst eng 340 (talk) 00:37, 13 February 2017 (UTC)

Proposed major revision

Hi all, I am a graduate student in chemistry. I have been assigned to edit this page as part of a class project. Our class is working closely with Wiki Education, who have made a point to educate us on the Wikipedia codes of conduct and etiquette. So I would like to pose and get feedback on the following revision of the lead section of this page before implementing it. Disclaimer: this lead section is still being edited by myself and peers. All comments, questions, and suggestions are welcome.

A molecular solid is a subcategory of a crystalline solid consisting of discrete atoms or molecules held together in a uniform, repeating order by a collection of intermolecular interactions.[1-9] Examples of intermolecular interactions include van der Waals forces, dipole forces, hydrogen bonding, quadrupole forces, and in some molecular solids, coulombic interactions.[1-9] Van der Waals forces, dipole forces, hydrogen bonding, and quadrupole forces differ in their physical and chemical origin from the metallic, ionic (coulombic), and covalent bond.[6,10] This difference in the type of force results in substantial differences in both the physical strength and electronic configuration of these intermolecular forces.[6,10] Van der Waals, dipole forces, hydrogen bonding, and quadrupole forces (2-127 kJ mol-1)[10] are typically much weaker than the forces holding together other crystalline solids: metallic (metallic bonding, 400-500 kJ mol-1),[2] ionic (Coulomb’s forces, 700-900 kJ mol-1),[2] and network solids (covalent bonds, 150-900 kJ mol-1).[2,10] Additionally, these intermolecular interactions, similar to ionic bonds, do not involve highly delocalized or shared electrons, unlike metallic and covalent bonds. These differences give rise to the commonly anisotropic mechanical, electronic, and thermal properties of molecular solids from other crystalline solids.[1-3,6]

For instance, molecular solids are typically poor conductors, considered relatively soft, and have low melting and boiling temperatures.[1-7] Examples of molecular solids range from condensed monoatomic gases (i.e. noble gases) to small molecules (i.e. naphthalene and water) to large molecules with tens of atoms (i.e. fullerene with 60 carbon atoms).

[1] Hall, G. Molecular Solid State Physics; Springer-Verlag: Berlin, Germany, 1965. [2] Fahlman, B. D. Materials Chemistry; Springer: Berlin, Germany, 2011. [3] Schwoerer, M.; Wolf, H. C. Organic Molecular Solids; Wiley-VCH: Weinheim, Germany, 2007. [4] Omar, M. A. Elementary Solid State Physics; Pearson: London, United Kingdom, 2002. [5] Patterson, J.; Bailey, B. Solid-State Physics; Springer: Berlin, Germany, 2010. [6] Turton, R. The Physics of Solids; Oxford University Press Inc: New York, New York, 2010. [7] Keer, H. V. Principles of the Solid State; Wiley Eastern Limited, Hoboken, New Jersey, 1993. [8] Cohen, M. J.; Coleman, L. B.; Garito, A. F.; Heeger, A. J. Electrical Conductivity of Tetrathiofulvalinium Tetracyanoquinodimethan (TTF) (TCNQ), Phys. Rev. B 1974, 10, 1298-1307. [9] El-Ghayoury, A. Mézière, C.; Simonov, S.; Zorina, L.; Cobián, M.; Canadell, E.; Rovira, C.; Náfrádi, B.; Sipos, B.; Forró, L.; Batail, P. A Neutral Zwitterionic Molecular Solid. Chem. Eur. J. 2010, 16, 14051-14059. [10] Israelachvili, J. N. Intermolecular and Surface Forces; Academic Press: Cambridge, Massachussetts, 2011.

Please, let me know what you all think. I will be adding other sections and content, but I wanted to discuss this revision before moving forward. Cryst eng 340 (talk) 00:36, 13 February 2017 (UTC)

Is a polymer a molecular solid?

In addition to the "Proposed major revision", I would like to bring up the question of whether or not a polymer is a molecular solid. Many of the sources I have cited above state a polymer is a molecular solid.[1-3] Many other texts simply do not address polymers or are ambiguous about their designation.[4-7] Has anyone come across this discrepancy as well? Has anyone come across a convincing argument on whether they are or are not a molecular solid?

[1] Hall, G. Molecular Solid State Physics; Springer-Verlag: Berlin, Germany, 1965. [2] Fahlman, B. D. Materials Chemistry; Springer: Berlin, Germany, 2011. [3] Schwoerer, M.; Wolf, H. C. Organic Molecular Solids; Wiley-VCH: Weinheim, Germany, 2007. [4] Omar, M. A. Elementary Solid State Physics; Pearson: London, United Kingdom, 2002. [5] Patterson, J.; Bailey, B. Solid-State Physics; Springer: Berlin, Germany, 2010. [6] Turton, R. The Physics of Solids; Oxford University Press Inc: New York, New York, 2010. [7] Keer, H. V. Principles of the Solid State; Wiley Eastern Limited, Hoboken, New Jersey, 1993. Cryst eng 340 (talk) 01:02, 13 February 2017 (UTC)

Molecular solids are option (A) crystalline, (B) amorphus (C) ionic, (D) metallic

Please give me crroct answer😇😇 2409:4042:2D8C:CC0:0:0:21C9:9900 (talk) 11:41, 13 December 2021 (UTC)

Wiki Education assignment: Electronic Structure and Applications of Materials Chem 485

This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 January 2022 and 18 March 2022. Further details are available on the course page. Student editor(s): Wongzh (article contribs).