Condensation energies for metals on glass and other substrates

Earlier work on condensation phenomena is briefly reviewed, and existing measurements of condensation energies are summarized. Measurements of condensation energies have been made for aluminium, silver and cadmium on glass and for aluminium and silver on single-crystal cleavage surfaces of sodium chloride and potassium bromide. Adhesive energies or binding energies between film and substrate have been calculated in each case. Association energies for nucleation are obtained by difference and shown to be consistent. Results for cadmium show good agreement with earlier work, but results for aluminium do not agree with the earlier results of Rhodin who measured the condensation energies for aluminium on various substrates, obtaining values which suggest chemisorption. These results appear to be too high and a possible explanation is given. It is concluded that the adhesive energy is due to physical adsorption and can be explained in terms of van der Waals forces only.

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Success or Failure of Chiral Crystallization of Similar Heterocyclic Compounds

Molecules ◽

10.3390/molecules25235691 ◽

2020 ◽

Vol 25 (23) ◽

pp. 5691

Author(s):

Cyprian M. Chunkang ◽

Iris E. Ikome ◽

Emmanuel N. Nfor ◽

Yuta Mitani ◽

Natsuki Katsuumi ◽

...

Keyword(s):

Hydrogen Bonds ◽

Single Crystal ◽

Single Crystals ◽

Heterocyclic Compounds ◽

Van Der Waals ◽

Van Der Waals Forces ◽

The Other ◽

X Ray ◽

Other Hand

Single crystals of two achiral and planar heterocyclic compounds, C9H8H3O(CA1) and C8H5NO2 (CA4), recrystallized from ethanol, were characterized by single crystal X-ray analysis, respectively, and chiral crystallization was observed only for CA1 as P212121 (# 19), whereas it was not observed for CA4 P21/c (# 14). In CA1, as a monohydrate, the hydrogen bonds were pronounced around the water of crystallization (O4), and the planar cyclic sites were arranged in parallel to slightly tilted positions. On the other hand, an anhydride CA4 formed a dimer by hydrogen bonds between adjacent molecules in the crystal, which were aggregated by van der Waals forces and placed in parallel planar cyclic sites.

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Molekül-und Kristallstrukturen des Dibrom- und Dijodmaleinsäurethioanhydrids Zum Verständnis der Korrelation zwischen / Crystal Structures of Dibrom- and Diiod Maleic Acid Thioanhydride

Zeitschrift für Naturforschung A ◽

10.1515/zna-1980-0104 ◽

1980 ◽

Vol 35 (1) ◽

pp. 14-17 ◽

Cited By ~ 1

Author(s):

Walter Gonschorek

Keyword(s):

Single Crystal ◽

Crystal Structures ◽

Maleic Acid ◽

Van Der Waals ◽

Van Der Waals Forces ◽

Space Group ◽

X Ray ◽

Lattice Constants ◽

Molecular And Crystal Structures

Abstract The molecular and crystal structures of dibrom maleic acid thioanhydride and diiod maleic acid thioanhydride have been determined by means of single-crystal X-ray intensities. The crystal structures are isomorphous and have the space group P41212 (enantiomorphous with P43212). The lattice constants are a = 7.543 Å, c = 12.155 Å (DBMTA) and a = 7.816 Å, c = 12.348 Å (DIMTA). The five-membered rings of the molecules are planar with maximum deviations of 0.003 Å (DBMTA) and 0.005 Å (DIMTA). Adjacent molecules are held together by van-der-Waals-forces.

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Crystal and Molecular Structure of cis-2,2',3',2"-Tetraacetoxy-1,1':4',1"-ternaphthyl

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19960726 ◽

1996 ◽

Vol 61 (5) ◽

pp. 726-732

Author(s):

Jaroslav Podlaha ◽

Ivana Císařová ◽

Martin Bělohradský ◽

Jiří Závada

Keyword(s):

Molecular Structure ◽

Single Crystal ◽

Title Compound ◽

Crystal And Molecular Structure ◽

Van Der Waals ◽

Van Der Waals Forces ◽

X Ray Diffraction ◽

X Ray ◽

The Mean ◽

Configuration And Conformation

The configuration and conformation of the title compound as a representative of conformationally locked ternaphthyls was determined by single-crystal X-ray diffraction. The arrangement of the mean planes of naphthyl and acetoxy groups results from intramolecular van der Waals forces.

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Self-Assembly of a Chiral Cubic Three-Connected Net from the High Symmetry Molecules C60 and SnI4

10.26434/chemrxiv.12196788 ◽

2020 ◽

Author(s):

Daniel B. Straus ◽

Robert J. Cava

Keyword(s):

Organic Synthesis ◽

Self Assembly ◽

Van Der Waals ◽

Van Der Waals Forces ◽

High Symmetry ◽

Molecular Chirality ◽

Chiral Materials ◽

Self Assembled ◽

Chiral Centers

The design of new chiral materials usually requires stereoselective organic synthesis to create molecules with chiral centers. Less commonly, achiral molecules can self-assemble into chiral materials, despite the absence of intrinsic molecular chirality. Here, we demonstrate the assembly of high-symmetry molecules into a chiral van der Waals structure by synthesizing crystals of C60(SnI4)2 from icosahedral buckminsterfullerene (C60) and tetrahedral SnI4 molecules through spontaneous self-assembly. The SnI4 tetrahedra template the Sn atoms into a chiral cubic three-connected net of the SrSi2 type that is held together by van der Waals forces. Our results represent the remarkable emergence of a self-assembled chiral material from two of the most highly symmetric molecules, demonstrating that almost any molecular, nanocrystalline, or engineered precursor can be considered when designing chiral assemblies.

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Measurement of growth rates for single crystals and pressed tablets of CuSO4.5 H2O on a rotating disc

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19892951 ◽

1989 ◽

Vol 54 (11) ◽

pp. 2951-2961 ◽

Cited By ~ 2

Author(s):

Miloslav Karel ◽

Jaroslav Nývlt

Keyword(s):

Growth Rate ◽

Single Crystal ◽

Single Crystals ◽

Growth Rates ◽

Diffusion Coefficients ◽

Preferred Orientation ◽

Rotating Disc ◽

Dissolution Rates ◽

Rates Of Growth ◽

Good Agreement

Measured growth and dissolution rates of single crystals and tablets were used to calculate the overall linear rates of growth and dissolution of CuSO4.5 H2O crystals. The growth rate for the tablet is by 20% higher than that calculated for the single crystal. It has been concluded that this difference is due to a preferred orientation of crystal faces on the tablet surface. Calculated diffusion coefficients and thicknesses of the diffusion and hydrodynamic layers in the vicinity of the growing or dissolving crystal are in good agreement with published values.

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A DFT study of spherands containing five anisyl groups — Highly preorganized to bind the alkali metal

Canadian Journal of Chemistry ◽

10.1139/v06-130 ◽

2006 ◽

Vol 84 (8) ◽

pp. 1045-1049 ◽

Cited By ~ 4

Author(s):

Shabaan AK Elroby ◽

Kyu Hwan Lee ◽

Seung Joo Cho ◽

Alan Hinchliffe

Keyword(s):

Density Functional Theory ◽

Binding Energy ◽

Density Functional ◽

Ionic Radius ◽

Binding Energies ◽

Cavity Size ◽

X Ray Diffraction ◽

Functional Theory ◽

X Ray ◽

Good Agreement

Although anisyl units are basically poor ligands for metal ions, the rigid placements of their oxygens during synthesis rather than during complexation are undoubtedly responsible for the enhanced binding and selectivity of the spherand. We used standard B3LYP/6-31G** (5d) density functional theory (DFT) to investigate the complexation between spherands containing five anisyl groups, with CH2–O–CH2 (2) and CH2–S–CH2 (3) units in an 18-membered macrocyclic ring, and the cationic guests (Li+, Na+, and K+). Our geometric structure results for spherands 1, 2, and 3 are in good agreement with the previously reported X-ray diffraction data. The absolute values of the binding energy of all the spherands are inversely proportional to the ionic radius of the guests. The results, taken as a whole, show that replacement of one anisyl group by CH2–O–CH2 (2) and CH2–S–CH2 (3) makes the cavity bigger and less preorganized. In addition, both the binding and specificity decrease for small ions. The spherands 2 and 3 appear beautifully preorganized to bind all guests, so it is not surprising that their binding energies are close to the parent spherand 1. Interestingly, there is a clear linear relation between the radius of the cavity and the binding energy (R2 = 0.999).Key words: spherands, preorganization, density functional theory, binding energy, cavity size.

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Nanotube‐Based 1D Heterostructures Coupled by van der Waals Forces

Small ◽

10.1002/smll.202102585 ◽

2021 ◽

pp. 2102585

Author(s):

Sofie Cambré ◽

Ming Liu ◽

Dmitry Levshov ◽

Keigo Otsuka ◽

Shigeo Maruyama ◽

...

Keyword(s):

Van Der Waals ◽

Van Der Waals Forces

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Tuning adlayer-substrate interactions of graphene/h-BN heterostructures on Cu(111)–Ni and Ni(111)–Cu surface alloys

RSC Advances ◽

10.1039/d0ra08622c ◽

2021 ◽

Vol 11 (4) ◽

pp. 1916-1927

Author(s):

Jianmei Huang ◽

Qiang Wang ◽

Pengfei Liu ◽

Guang-hui Chen ◽

Yanhui Yang

Keyword(s):

Long Range ◽

Van Der Waals ◽

Van Der Waals Forces ◽

Alloy Surface ◽

Surface Alloys ◽

Substrate Interactions

The evolution of the interface and interaction of h-BN and graphene/h-BN (Gr/h-BN) on Cu(111)–Ni and Ni(111)–Cu surface alloys versus the Ni/Cu atomic percentage on the alloy surface were comparatively studied by DFT-D2, including critical long-range van der Waals forces.

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