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The '''mesomeric effect''' or '''resonance effect''' in [[chemistry]] is a property of [[substituent]]s or [[functional group]]s in a [[chemical compound]]. The effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant [[resonance structure]]s and is symbolized by the letter '''M'''. The mesomeric effect is negative ('''-M''') when the substituent is an electron-withdrawing group and the effect is positive ('''+M''') when based on resonance the substituent is an electron releasing group.
'''Baroque art''' is the [[painting]] and [[sculpture]] associated with the [[Baroque]] [[cultural movement]], a movement often identified with [[political absolutism|Absolutism]] and the [[Counter Reformation]]; the existence of important Baroque art and architecture in non-absolutist and Protestant states, however, undercuts this linking.
*Examples of -M substituents: [[acetyl]] (UPAC ethanoyl) - [[nitrile]] - [[nitro]]
== Painting ==
*Examples of +M substituents: [[alcohol]] - [[amine]]
The [[Council of Trent]] (1545-63), in which the [[Catholicism|Roman Catholic Church]] answered many questions of internal reform raised by both [[Protestantism|Protestants]] and by those who had remained inside the Catholic Church, addressed the representational arts by demanding that paintings and sculptures in church contexts should speak to the illiterate rather than to the well-informed. Due to this Baroque art tends to focus on Saints, the Virgin Mary, and other well known bible stories. This turn toward a populist conception of the function of ecclesiastical art is seen by many [[Art history|art historians]] as driving the innovations of [[Michelangelo Merisi|Caravaggio]] and the [[Carracci]] brothers, all of whom were working (and competing for commissions) in Rome around 1600.
The net electron flow from or to the substituent is determined also by the [[inductive effect]]. It's important to note that the mesomeric effect as a result of p - orbital overlap (resonance) has absolutely no effect on this inductive effect, as the inductive effect is purely to do with the [[electronegativity]] of the atoms and their structural chemistry (which atoms are connected to which).
Baroque art is characterized by great drama, rich deep color, and intense light and dark shadows. As opposed to Renaissance art, which usually showed the moment before an event took place, Baroque artists chose the most dramatic point, the moment when the action was occurring: Michelangelo, working in the High Renaissance, shows his David composed and still before he battles Goliath; Bernini's baroque David is caught in the act of hurling the stone at the giant. Baroque art was meant to evoke emotion and passion instead of the calm rationality that had been prized during the Renaissance.
The concepts of mesomeric effect, '''mesomerism''' and '''mesomer''' were introduced by [[Christopher Kelk Ingold|Ingold]] in 1938 as an alternative to the [[Linus Pauling|Pauling's]] synonymous concept of [[resonance effect|resonance]] <ref>''If It's Resonance, What Is Resonating?'' Kerber, Robert C. . J. Chem. Educ. '''2006''' 83 223. [http://www.jce.divched.org/Journal/Issues/2006/Feb/abs223.html Abstract]</ref>. Mesomerism is in this context is often encountered in German and French literature but in English literature the term resonance dominates.
===Notable Baroque Painters===
===Italian===
*[[Caravaggio]] (1571-1610)
*[[Guercino]]*[[Annibale Carracci]] (1560-1609)
*[[Orazio Gentileschi]] (1563-1639)
*[[Artemisia Gentileschi]] (1592-1652/53)
*[[Agostino Carracci]]
*[[Ludovico Carracci]]
===French= External links==
* IUPAC [[Gold Book]] [http://www.iupac.org/goldbook/M03844.pdf definition]
*[[Georges de La Tour]] (1590-1652)
*'''[[Nicolas Poussin]]''' (c. 1594-1665)
*[[Claude Gellee]] (1600-1682)
*[[Hyacinthe Rigaud]] (1659-1743)
===Spanish===
*'''[[Velázquez]]'''
===Dutch===
*'''[[Rembrandt Harmenszoon van Rijn|Rembrandt]]'''
*[[Franz Hals]]
*[[Vermeer]]
*[[Ruisdael]]
===Flemish= See also ==
* [[List of publications in chemistry#Organic chemistry|Important publications in organic chemistry]]
*'''[[Peter Paul Rubens]]'''
== SculptureReferences ==
<references />
The most important sculptor of the Baroque period was undoubtedly [[Gianlorenzo Bernini]] (1598-1680), who approached [[Michelangelo Buonarroti|Michelangelo]] in his multiple skills. Bernini sculpted, worked as an architect, painted, wrote plays, and staged spectacles. In the late 20th century Bernini was most valued for his sculpture, both for his virtuosity in carving marble and his ability to create figures that combine the physical and the spiritual. He was also a fine portraitist in high demand among the powerful for bust-length likenesses.
[[Category:Chemical bonding]]
===Baroque Sculptors and Architects===
*'''[[Gian Lorenzo Bernini]]''' (1598-1680)
*[[Francesco Borromini]] (1599-1667)
*[[Claude Perrault]] (1613-1688), French
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[[Category:Baroque art| Baroque art]]
[[zh:巴洛克艺术]]
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