Search results
Results from the WOW.Com Content Network
Metallic bonding is a type of chemical bonding that arises from the electrostatic attractive force between conduction electrons (in the form of an electron cloud of delocalized electrons) and positively charged metal ions. It may be described as the sharing of free electrons among a structure of positively charged ions .
In the 1970s, Paolo Chini demonstrated that very large clusters could be prepared from the platinum metals, one example being [Rh 13 (CO) 24 H 3] 2−. This area of cluster chemistry has benefited from single-crystal X-ray diffraction. Structure of Rh 4 (CO) 12, a metal carbonyl cluster. Many metal carbonyl clusters contain ligands aside from CO.
In inorganic chemistry, metal–metal bonds describe attractive interactions between metal centers. The simplest examples are found in bimetallic complexes. Metal–metal bonds can be "supported", i.e. be accompanied by one or more bridging ligands, or "unsupported". They can also vary according to bond order.
A less often mentioned type of bonding is metallic bonding. In this type of bonding, each atom in a metal donates one or more electrons to a "sea" of electrons that reside between many metal atoms. In this sea, each electron is free (by virtue of its wave nature) to be associated with a great many atoms at once. The bond results because the ...
Metallic solids are held together by a high density of shared, delocalized electrons, resulting in metallic bonding. Classic examples are metals such as copper and aluminum, but some materials are metals in an electronic sense but have negligible metallic bonding in a mechanical or thermodynamic sense (see intermediate forms).
The classical model identifies three main types of chemical bonds — ionic, covalent, and metallic — distinguished by the degree of charge separation between participating atoms. [3] The characteristics of the bond formed can be predicted by the properties of constituent atoms, namely electronegativity.
O-donors [definition needed] such as HPO 2− 4 were abundant in the prebiotic atmosphere. [6] Metal ion binding to such O-donors was required to build the biological polymers, since the bond is generally weak, it can catalyze the required reaction and dissociate after (i.e. Mg 2+ in DNA synthesis).
The metal–ligand bond can be further stabilised by a formal donation of electron density back to the ligand in a process known as back-bonding. In this case a filled, central-atom-based orbital donates density into the LUMO of the (coordinated) ligand. Carbon monoxide is the preeminent example a ligand that engages metals via back-donation.