97:
687:
681:
693:
313:
The rate of reaction for many reactions involving unimolecular heterolysis depends heavily on rate of ionization of the covalent bond. The limiting reaction step is generally the formation of ion pairs. One group in
Ukraine did an in-depth study on the role of
340:. The main factors that affect heterolysis rates are mainly the solvent's polarity and electrophilic as well as its ionizing power. The polarizability, nucleophilicity and cohesion of the solvent had a much weaker effect on heterolysis.
343:
However, there is some debate on effects of the nucleophilicity of the solvent, some papers claim it has no effect, while some papers claim that more nucleophilic solvents decrease the reaction rate.
431:
Pauling, L. (1932). "The Nature of the
Chemical Bond. IV. The Energy of Single Bonds and the Relative Electronegativity of Atoms". Journal of the American Chemical Society. 54 (9): 3570ā3582.
301:
in his 1884 dissertation. Arrhenius pioneered development of ionic theory and proposed definitions for acids as molecules that produced hydrogen ions, and bases as molecules that produced
245:
175:
376:
780:
275:
developed the concept of the electron-pair bond, in which two atoms share one to six electrons, thus forming the single electron bond, a single bond, a
898:
825:
506:
405:
Blanksby, S. J.; Ellison, G. B. (2003). "Bond
Dissociation Energies of Organic Molecules". Acc. Chem. Res. 36 (4): 255ā263. doi:10.1021/ar020230d.
443:
Dvorko, G. F., Ponomareva, E. A. and
Ponomarev, M. E. (2004), "Role of nucleophilic solvation and the mechanism of covalent bond heterolysis".
268:
The discovery and categorization of heterolytic bond fission was clearly dependent on the discovery and categorization of the chemical bond.
481:
Armentrout, P. B., and Jack Simons. "Understanding heterolytic bond cleavage". Journal-American
Chemical Society 114 (1992): 8627-8627.
422:
Lewis, Gilbert N. (1916). "The Atom and the
Molecule". Journal of the American Chemical Society. 38 (4): 772. doi:10.1021/ja02261a002.
321:
and its effect on the mechanism of bond heterolysis. They found that the rate of heterolysis depends strongly on the nature of the
760:
745:
569:
596:
557:
547:
552:
499:
31:
294:, which also introduced the idea that electrons in a covalent bond may not be shared evenly between the bonded atoms.
924:
820:
815:
805:
795:
770:
740:
586:
357:
111:
192:
114:, which is similar (but not equivalent) to homolytic bond dissociation energy commonly used to represent the
750:
722:
492:
135:
891:
852:
352:
91:
atom keeps the pair of electrons becoming anionic while the more electropositive atom becomes cationic.
886:
810:
701:
564:
523:
712:
576:
542:
464:
Abraham MH, Doherty RM, Kamlet JM, Harris JM, Taft RW.J. Chem. Soc., Perkin Trans. 2 1987; 913ā920.
333:
876:
631:
336:(t-BuCl) heterolysis by 14 orders of magnitude. This is caused by very strong solvation of the
862:
651:
611:
601:
406:
291:
88:
903:
686:
643:
616:
448:
390:
337:
298:
272:
72:
755:
626:
881:
17:
96:
790:
591:
50:
918:
839:
799:
732:
661:
534:
515:
287:
68:
386:
785:
315:
79:
from the other species. During heterolytic bond cleavage of a neutral molecule, a
121:
One example of the differences in the energies is the energy required to break a
871:
621:
381:
280:
276:
115:
104:
680:
385:, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "
606:
581:
394:
318:
302:
38:
410:
27:
Breaking a molecular bond such that both electrons remain with one species
76:
322:
329:
80:
452:
692:
84:
484:
110:
The energy required to break the bond is called the heterolytic
488:
297:
However, the ions had been studied before bonds mainly by
207:
150:
67: 'loosening') is the process of cleaving/breaking a
473:
Gajewski JJ. J. Am. Chem. Soc. 2001; 123: 10877ā10883.
195:
138:
107:; the process usually produces two fragment species.
861:
838:
769:
731:
711:
700:
660:
642:
533:
522:
239:
169:
328:For example, a change of reaction medium from
500:
283:. This became the model for a covalent bond.
103:Heterolytic fission almost always happens to
8:
708:
530:
507:
493:
485:
87:will be generated. Most commonly the more
230:
217:
206:
201:
196:
194:
159:
149:
144:
139:
137:
899:Polyhedral skeletal electron pair theory
240:{\displaystyle {\ce {H2 -> H+ + H-}}}
439:
437:
369:
7:
170:{\displaystyle {\ce {H2 -> 2H.}}}
382:Compendium of Chemical Terminology
25:
691:
685:
679:
95:
332:to water increases the rate of
290:first proposed the concept of
210:
153:
60: 'different' and
1:
75:takes both original bonding
71:where one previously bonded
32:Heterolysis (disambiguation)
941:
597:Metalāligand multiple bond
29:
677:
387:heterolysis (heterolytic)
255:= 66 kcal/mol (in water)
18:Heterolytic bond cleavage
358:Bond dissociation energy
112:bond dissociation energy
395:10.1351/goldbook.H02809
241:
171:
353:Homolysis (chemistry)
242:
172:
587:Coordinate (dipolar)
193:
136:
30:For other uses, see
761:CāHĀ·Ā·Ā·O interaction
543:Electron deficiency
445:J. Phys. Org. Chem.
334:tert-Butyl chloride
209:
152:
47:heterolytic fission
925:Chemical reactions
746:Resonance-assisted
237:
197:
167:
140:
912:
911:
863:Electron counting
834:
833:
723:London dispersion
675:
674:
652:Metal aromaticity
309:Solvation effects
292:electronegativity
271:In 1916, chemist
259:
258:
229:
216:
200:
162:
143:
16:(Redirected from
932:
904:Jemmis mno rules
756:Dihydrogen bonds
709:
695:
689:
683:
617:Hyperconjugation
531:
509:
502:
495:
486:
474:
471:
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462:
456:
441:
432:
429:
423:
420:
414:
403:
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338:transition state
299:Svante Arrhenius
273:Gilbert N. Lewis
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21:
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773:
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714:
704:
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671:
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638:
526:
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513:
478:
477:
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468:
463:
459:
453:10.1002/poc.757
447:, 17: 825ā836.
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421:
417:
404:
400:
375:
371:
366:
349:
311:
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213:
191:
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185:= 104 kcal/mol
134:
133:
122:
89:electronegative
35:
28:
23:
22:
15:
12:
11:
5:
938:
936:
928:
927:
917:
916:
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829:
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763:
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753:
748:
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719:
717:
706:
702:Intermolecular
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619:
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584:
579:
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573:
572:
562:
561:
560:
555:
550:
539:
537:
528:
524:Intramolecular
520:
519:
516:Chemical bonds
514:
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504:
497:
489:
483:
482:
476:
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466:
457:
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398:
368:
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355:
348:
345:
310:
307:
265:
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256:
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233:
225:
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187:
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179:
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165:
158:
155:
147:
101:
100:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
937:
926:
923:
922:
920:
905:
902:
900:
897:
893:
890:
888:
885:
883:
880:
878:
877:HĆ¼ckel's rule
875:
874:
873:
870:
869:
867:
864:
860:
854:
851:
849:
846:
845:
843:
841:
840:Bond cleavage
837:
827:
824:
822:
819:
817:
814:
812:
809:
807:
806:Intercalation
804:
801:
797:
796:Metallophilic
794:
792:
789:
787:
784:
782:
779:
778:
776:
772:
768:
762:
759:
757:
754:
752:
749:
747:
744:
742:
739:
738:
736:
734:
730:
724:
721:
720:
718:
716:
713:Van der Waals
710:
707:
703:
699:
694:
688:
682:
668:
667:
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551:
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540:
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529:
525:
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510:
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479:
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341:
339:
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304:
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295:
293:
289:
288:Linus Pauling
284:
282:
278:
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269:
263:
254:
250:
248:
231:
223:
218:
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189:
188:
184:
180:
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163:
156:
145:
132:
131:
128:
127:
126:
119:
117:
113:
108:
106:
98:
94:
93:
92:
90:
86:
82:
78:
74:
70:
69:covalent bond
66:
62:
59:
55:
52:
48:
44:
40:
33:
19:
882:Baird's rule
847:
602:Charge-shift
565:Hypervalence
469:
460:
444:
427:
418:
401:
380:
372:
342:
327:
316:nucleophilic
312:
296:
285:
270:
267:
252:
182:
120:
116:energy value
109:
105:single bonds
102:
64:
61:
57:
54:
46:
42:
36:
872:Aromaticity
848:Heterolysis
826:Salt bridge
771:Noncovalent
741:Low-barrier
622:Aromaticity
612:Conjugation
592:Pi backbond
281:triple bond
277:double bond
118:of a bond.
43:heterolysis
800:aurophilic
781:Mechanical
364:References
49:(from
892:spherical
853:Homolysis
816:Cationāpi
791:Chalcogen
751:Symmetric
607:Hapticity
319:solvation
303:hydroxide
232:−
211:⟶
164:⋅
154:⟶
77:electrons
58:(heteros)
39:chemistry
919:Category
821:Anionāpi
811:Stacking
733:Hydrogen
644:Metallic
535:Covalent
527:(strong)
411:12693923
347:See also
286:In 1932
786:Halogen
632:bicyclo
577:Agostic
323:solvent
279:, or a
264:History
83:and an
73:species
65:(lusis)
887:Mƶbius
715:forces
705:(weak)
409:
330:hexane
305:ions.
81:cation
56:į¼ĻĪµĻĪæĻ
865:rules
774:other
662:Ionic
570:3cā4e
558:8cā2e
553:4cā2e
548:3cā2e
377:IUPAC
125:bond
85:anion
63:Ī»ĻĻĪ¹Ļ
53:
51:Greek
627:homo
582:Bent
407:PMID
449:doi
391:doi
389:".
325:.
123:HāH
45:or
37:In
921::
436:^
379:,
41:,
802:)
798:(
508:e
501:t
494:v
455:.
451::
413:.
393::
253:H
251:Ī
228:H
224:+
219:+
215:H
203:2
199:H
183:H
181:Ī
161:H
157:2
146:2
142:H
34:.
20:)
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