Dicyclopentadiene is an asymmetrical dimer of two cyclopentadiene molecules that have reacted in a Diels-Alder reaction to give the product.

For boiling to occur, either the dimer bonds must be broken, or the entire dimer arrangement must be vaporised, both of which increase enthalpy of vaporisation requirements significantly.

In fact, it includes weakly bound species that would not traditionally be considered molecules, such as the helium dimer, He < sub > 2 </ sub >, which has one vibrational bound state and is so loosely bound that it is only likely to be observed at very low temperatures.

( 2006 ) -- tooltips must be positioned with great accuracy to avoid bonding the dimer incorrectly.

Likewise, AuBr < sub > 3 </ sub > can be formed from the elements and exists primarily as the dimer Au < sub > 2 </ sub > Br < sub > 6 </ sub >.

Subunits may be arranged in dimers or hexamers depending on species, the dimer or hexamer complex is likewise arranged in chains or clusters in weights exceeding 1500 kDa.

A dimer is a chemical entity consisting of two structurally similar monomers joined by bonds that can be either strong or weak, covalent or intermolecular.

For example, the 2006 paper in this continuing research effort by Freitas, Merkle and their collaborators reports that the most-studied mechanosynthesis tooltip motif ( DCB6Ge ) successfully places a C < sub > 2 </ sub > carbon dimer on a C ( 110 ) diamond surface at both 300 K ( room temperature ) and 80 K ( liquid nitrogen temperature ), and that the silicon variant ( DCB6Si ) also works at 80 K but not at 300 K. These tooltips are intended to be used only in carefully controlled environments ( e. g., vacuum ).

Maximum acceptable limits for tooltip translational and rotational misplacement errors are reported in paper III — tooltips must be positioned with great accuracy to avoid bonding the dimer incorrectly.

The first to be reported was a cyclic dimer, C < sub > 8 </ sub > H < sub > 16 </ sub > O < sub > 4 </ sub >, in 1906.

# Calcium binding changes the shape of troponin, causing tropomyosin to be moved deeper into the groove of the actin dimer, therefore causing the myosin binding sites on the actin to be exposed.

The dimer does not materialize but a reaction with iodine in benzene followed by reaction with the tri-tert-butyl sila anion results in the formation of an eight membered silicon cluster compound which can be described as a Si < sub > 2 </ sub > dumbbell ( length 229 picometer and with inversion of tetrahedral geometry ) sandwiched between two almost parallel Si < sub > 3 </ sub > rings.

The dimer method can be used to find possible transition states without knowledge of the final structure or to refine a good guess of a transition structure.

Specifically it would be called a dimer if it contains two subunits, a trimer if it contains three subunits, and a tetramer if it contains four subunits.

This substance can be considered as a dimer of the hypothetical cobalt tetracarbonyl, Co ( CO )< sub > 4 </ sub >.

* Step 1: in the first step of IF assembly two parallel, unstaggered intermediate filament polypeptides chains form a dimer via their a-helical rod domains ; these dimers can be either homodimers or heterodimers.

Some ruthenium complexes, such as the dinuclear µ-oxo-bridged " blue dimer " ( the first of its kind to be synthesized ), are capable of light-driven water oxidation, thanks to being able to form high valence states.

In this way, each subunit contributes to the binding site on the neighbouring subunit, and so the tetramer can also be considered a dimer of functional dimers.

( 2006 ) ( in the continuing research effort by Freitas, Merkle and their collaborators ) reports that the most-studied mechanosynthesis tooltip motif ( DCB6Ge ) successfully places a C < sub > 2 </ sub > carbon dimer on a C ( 110 ) diamond surface at both 300 K ( room temperature ) and 80 K ( liquid nitrogen temperature ), and that the silicon variant ( DCB6Si ) also works at 80 K but not at 300 K. Over 100, 000 CPU hours were invested in this latest study.

The N-terminal tail of histone H4, on the other hand, has a region of highly basic amino acids ( 16-25 ), which, in the crystal structure, forms an interaction with the highly acidic surface region of a H2A-H2B dimer of another nucleosome, being potentially relevant for the higher-order structure of nucleosomes.

Although an early paper gives a predicted placement speed of 1 dimer per second for this tooltip, this limit was imposed by the slow speed of recharging the tool using an inefficient recharging method and is not based on any inherent limitation in the speed of use of a charged tooltip.

In 2004, Folding @ home was used to perform the first molecular dynamics study of the refolding of p53's protein dimer in explicit water which revealed insights that were previously unobtainable, and from it produced the first peer reviewed publication on cancer from a distributed computing project.

The “ dimer ” is formed by two images very close to each other on the PES.

Based on just three structures of the insulin dimer, trypsin-pancreatic trypsin inhibitor complex and oxyhaemoglobin, Cyrus Chothia and Joel Janin found that between 1, 130 and 1, 720 Angstroms < sup > 2 </ sup > of surface area was removed from contact with water indicating that hydrophobicity was the major factor stabilising protein-protein interactions.

MutS forms a dimer ( MutS < SUB > 2 </ SUB >) that recognises the mismatched base on the daughter strand and binds the mutated DNA.

The SNX-BAR dimer enters the nucleation complex via direct binding or lateral movement on endosomal surface.

Additionally, no sensing means was proposed for discriminating among the three possible outcomes of an attempted dimer placement — deposition at the correct location, deposition at the wrong location, and failure to place the dimer at all — because the initial proposal was to position the tooltip by dead reckoning, with the proper reaction assured by designing appropriate chemical energetics and relative bond strengths for the tooltip-surface interaction.

Molecular structure of a 14-3-3 protein dimer bound to a peptide.

To perform signal transduction, RTKs need to form dimers in the plasma membrane ; the dimer is stabilized by ligands binding to the receptor.

Under special conditions, most OH-containing molecules form dimers, e. g. the water dimer.

There are homotetramers ( all subunits are identical ) such as glutathione S-transferase or single-strand binding protein, dimers of hetero-dimers such as hemoglobin ( a dimer of an alpha / beta dimer ), and heterotetramers, where each subunit is different.

The C1a and C2a subdomains are homologous and form an intramolecular ' dimer ' that forms the active site.

These are the smallest of the AC enzyme classes ; the AC-IV from Yersinia is a dimer of 19 kDa subunits with no known regulatory components.

Several condensed matter systems are being studied with potential applications to quantum computation, including experimental systems like quantum dots, SQUIDs, and theoretical models like the toric code and the quantum dimer model.

They are predicted to contain two K < sub > V </ sub >- style six-transmembrane domains, suggesting they form a dimer in the membrane.

During polymerization, both the α-and β-subunits of the tubulin dimer are bound to a molecule of GTP.

The protein dimer contains 2 glycopeptidic subunits, labeled alpha and beta subunits, that are non-covalently associated ( i. e., without any disulfide bridge linking them ):

For example, acetic acid forms a dimer in the gas phase, where the monomer units are held together by hydrogen bonds.

Excimers are only formed when one of the dimer components is in the excited state.

The term excimer ( excited state complex ) is, strictly speaking, limited to cases in which a true dimer is formed ; that is, both components of the dimer are the same molecule or atom.

' Most " excimer " lasers are of the noble gas halide type, for which the term excimer is strictly speaking a misnomer ( since a dimer refers to a molecule of two identical or similar parts ): The correct but less commonly used name for such is exciplex laser.

The first is a dimer ( consists of two units ), while the others are tetramers ( four subunits ).

where and are the energies of the isolated objects ( monomers ), and the energy of their interacting assembly ( dimer ).

Phycoerythrins are the phycobiliproteins that bind the highest number of phycobilins ( up to six per alpha-beta subunit dimer ).

The subunits are frequently related to one another by symmetry operations, such as a 2-fold axis in a dimer.

The PDB accession codes for this protein are ,, ( 3BZ1 and 3BZ2 are monomeric structures of the Photosystem II dimer ),,,,,.

The electron transfer components of the reaction centre of PSI are a primary electron donor P-700 ( chlorophyll dimer ) and five electron acceptors: A0 ( chlorophyll ), A1 ( a phylloquinone ) and three 4Fe-4S iron-sulphur centres: Fx, Fa, and Fb.

Two monomers are likely co-translationally expressed in a way that facilitates their formation of a coiled-coil dimer, which is the basic subunit of vimentin assembly.

These 2 special pairs form an excitonic dimer, which means that they behave in function as a single entity ; i. e., they are excited as if they were a single molecule.

Within each dimer 2 miraculin glycoproteins are linked by a disulfide bridge.