299:
20:
314:
329:
344:
413:
gives rise to pentamethylcyclopentadienyl (Cp*) complexes. These ligands are more basic and more lipophilic. Replacing methyl groups with larger substituents results in cyclopentadienes that are so encumbered that pentaalkyl derivatives are no longer possible. Well-studied ligands of this type
391:
A pair of cyclopentadienyl ligands can be covalently linked giving rise to so-call ansa metallocenes. The angle between the two Cp rings is fixed. Rotation of the rings about the metal-centroid axis is stopped as well. A related class of derivatives give rise to the
197:. The MâCp bonding arises from overlap of the five Ď molecular orbitals of the Cp ligand with the s, p, and d orbitals on the metal. These complexes are referred to as Ď-complexes. Almost all of the
1628:
1149:
1186:
298:
648:
King, R. B.; Bisnette, M. B. (1967). "Organometallic chemistry of the transition metals XXI. Some Ď-pentamethylcyclopentadienyl derivatives of various transition metals".
690:
1036:
1216:
460:
Cp metal complexes are mainly used as stoichiometric reagents in chemical research. Ferrocenium reagents are oxidants. Cobaltocene is a strong, soluble reductant.
1253:
204:
In relatively rare cases, Cp binds to metals via only one carbon center. These types of interactions are described as Ď-complexes because they only have a
175:
1272:
1418:
1343:
1067:
1461:
82:-) bonding mode. The metalâcyclopentadienyl interaction is typically drawn as a single line from the metal center to the center of the Cp ring.
1208:
1016:
887:
527:
155:
1476:
1322:
1173:
1094:
1041:
683:
396:. In these cases, a Cp ligand as linked to a non-Cp ligand. Such complexes have been commercialized for the production of polypropylene.
313:
154:
Mixed-ligand Cp complexes containing Cp ligand and one or more other ligands. They are more numerous. One widely studied example is the
1724:
1059:
1011:
1568:
1334:
1289:
1245:
1229:
1031:
998:
988:
875:
208:
between the metal and the cyclopentadienyl group. Typical examples of this type of complex are group 14 metal complexes such as CpSiMe
1729:
1375:
1284:
1141:
940:
1603:
1598:
1563:
1237:
1200:
1195:
1161:
1003:
952:
917:
900:
892:
828:
768:
284:
Most Cp complexes are prepared by substitution of preformed Cp complexes by replacement of halide, CO, and other simple ligands.
1613:
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819:
807:
778:
773:
676:
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863:
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405:
343:
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All 5 carbon atoms of a Cp ligand are bound to the metal in the vast majority of MâCp complexes. This bonding mode is called
1411:
795:
263:
1314:
1136:
850:
447:
393:
320:
140:
was first developed in the 1950s. Bent metallocenes are represented by compounds of the type . Some are catalysts for
1669:
1674:
410:
1486:
259:
258:
of alkali-metal cyclopentadienyl compounds with transition metal chlorides. Sodium cyclopentadienide (NaCp) and
1522:
1427:
1404:
1298:
858:
713:
266:
255:
137:
269:(CpTl) are alternative sources. For the preparation of some particularly robust complexes, e.g. nickelocene,
1086:
328:
1703:
1588:
1181:
993:
574:
475:
452:
Constrained geometry complexes are related to ansa-metallocenes except that one ligand is not Cp-related.
171:
46:
23:
1623:
1021:
464:
304:
1578:
1441:
972:
699:
133:
38:
1362:
19:
1698:
1517:
1491:
1446:
1380:
1385:
1512:
1466:
1367:
1113:
718:
613:
494:
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605:
597:
523:
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486:
130:
1659:
1553:
1456:
1451:
657:
589:
575:"Arene-Bridged Dithorium Complexes: Inverse Sandwiches Supported by a δ Bonding Interaction"
570:
386:
335:
274:
198:
239:. Such complexes, sometimes called "slipped Cp complexes", are invoked as intermediates in
1532:
1527:
349:
270:
1649:
1548:
1471:
1131:
845:
240:
144:
661:
1718:
1644:
840:
745:
637:
617:
246:
Moreover, inverse sandwich compounds with the "metalâCpâmetal" structures are known.
236:
1573:
905:
490:
122:
114:
94:
106:
601:
569:
Yu, Chao; Liang, Jiefeng; Deng, Chong; Lefèvre, Guillaume; Cantat, Thibault;
1685:
1481:
191:
98:
75:
1396:
609:
231:
Still rarer, the Cp unit can bond to the metal via three carbons. In these
205:
668:
593:
148:
141:
170:). Monometallic compounds featuring only one Cp ring are often known as
541:
Organotransition Metal
Chemistry: Fundamental Concepts and Applications
129:). When the Cp rings are mutually parallel the compound is known as a
278:
277:
such as KOH. When only a single Cp ligand is installed, the other
74:). Cyclopentadienyl ligands almost invariably bind to metals as a
42:
18:
522:
Elschenbroich, C. "Organometallics" (2006) Wiley-VCH: Weinheim.
1400:
672:
147:. Metallocenes are often thermally stable, and find use as
16:
Coordination complex of a metal and cyclopentadienyl groups
1629:
Arene complexes of univalent gallium, indium, and thallium
105:), which has many analogues for other metals, such as
556:
558:(3rd ed.). New York, NY: John Wiley & Sons.
224:-Cp complexes are intermediates in the formation of
1683:
1637:
1541:
1505:
1434:
1355:
1265:
1106:
1079:
965:
933:
761:
730:
706:
636:
281:typically carbonyl, halogen, alkyl, and hydride.
543:. New York, NY: Wiley-Interscience. p. 105.
307:, a powerful reducing agent derived from "Cp*".
174:or as piano stool compounds, one example being
273:is employed in the presence of a conventional
97:. A famous example of this type of complex is
1412:
684:
235:-Cp complexes, the bonding resembles that in
8:
321:constrained geometry organotitanium complex
176:methylcyclopentadienylmanganese tricarbonyl
1513:Oxidative addition / reductive elimination
1419:
1405:
1397:
691:
677:
669:
1462:Polyhedral skeletal electron pair theory
582:Journal of the American Chemical Society
293:Variations of Cyclopentadienyl complexes
254:The compounds are generally prepared by
518:
516:
514:
510:
291:
93:cyclopentadienyl complexes are called
493:, these dihalides give catalysts for
7:
1569:Transition metal fullerene complexes
635:Shriver, D.; Atkins, P. W. (1999).
1604:Transition metal carbyne complexes
1599:Transition metal carbene complexes
1564:Transition metal indenyl complexes
485:are the basis of some reagents in
14:
1614:Transition metal alkyne complexes
1609:Transition metal alkene complexes
1619:Transition-metal allyl complexes
342:
327:
312:
297:
1594:Transition metal acyl complexes
201:employ this coordination mode.
151:in various types of reactions.
643:. New York, NY: W. H. Freeman.
442:Constrained geometry complexes
406:Bulky cyclopentadienyl ligands
394:constrained geometry complexes
1:
662:10.1016/S0022-328X(00)91042-8
264:Trimethylsilylcyclopentadiene
448:constrained geometry complex
1670:Shell higher olefin process
1477:DewarâChattâDuncanson model
212:. An example of both is (Cp
1746:
1725:Cyclopentadienyl complexes
1559:Cyclopentadienyl complexes
1523:β-hydride elimination
1497:Metalâligand multiple bond
573:; Huang, Wenliang (2020).
497:. Such species are called
445:
422:H (R = iso-Pr) and 1,2,4-C
411:Pentamethylcyclopentadiene
403:
384:
288:Variations of Cp complexes
1624:Transition metal carbides
260:lithium cyclopentadienide
256:salt metathesis reactions
250:Synthesis of Cp complexes
1730:Organometallic chemistry
1428:Organometallic chemistry
554:Crabtree, R. H. (2001).
267:cyclopentadienylthallium
220:). It is probable that
138:organometallic chemistry
35:cyclopentadienyl complex
28:cyclopentadienyl complex
1589:Half sandwich compounds
499:Kaminsky-type catalysts
241:ring slipping reactions
172:half sandwich compounds
47:cyclopentadienyl groups
1704:Bioinorganic chemistry
700:Coordination complexes
489:. Upon treatment with
30:
24:Zirconocene dichloride
1675:ZieglerâNatta process
1579:Metal tetranorbornyls
539:Yamamoto, A. (1986).
495:olefin polymerization
305:Decamethylcobaltocene
22:
1684:Related branches of
1442:Crystal field theory
594:10.1021/jacs.0c11215
571:Diaconescu, Paula L.
39:coordination complex
1699:Inorganic chemistry
1518:Migratory insertion
1492:Agostic interaction
1447:Ligand field theory
639:Inorganic Chemistry
588:(51): 21292â21297.
262:are commonly used.
1584:Sandwich compounds
1542:Types of compounds
1467:Isolobal principle
650:J. Organomet. Chem
31:
1712:
1711:
1694:Organic chemistry
1665:Olefin metathesis
1655:Grignard reaction
1554:Grignard reagents
1394:
1393:
528:978-3-527-29390-2
487:organic synthesis
199:transition metals
70:, abbreviated as
1737:
1660:Monsanto process
1457:d electron count
1452:18-electron rule
1421:
1414:
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560:
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400:Bulky Cp ligands
387:Ansa-metallocene
346:
336:ansa-metallocene
331:
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59:
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1549:Gilman reagents
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1533:Carbometalation
1528:Transmetalation
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629:Further reading
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463:Derivatives of
458:
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408:
402:
389:
383:
381:Ansa Cp ligands
376:
375:
371:
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363:
359:
355:
352:as found in (Bu
350:Bulky Cp ligand
347:
338:
332:
323:
317:
308:
302:
290:
271:cyclopentadiene
252:
228:-Cp complexes.
219:
215:
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169:
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161:
136:. This area of
128:
120:
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88:
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1650:Cativa process
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1392:
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1356:Halide donors:
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673:
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666:
656:(2): 287â297.
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623:
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531:
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481:
477:
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446:Main article:
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404:Main article:
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385:Main article:
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145:polymerization
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1645:Carbonylation
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1472:Ď backbonding
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237:allyl ligands
234:
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196:
195:-coordination
194:
186:Bonding modes
185:
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1638:Applications
1574:Metallocenes
1558:
1345:
1068:
653:
649:
638:
585:
581:
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456:Applications
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95:metallocenes
90:
89:
79:
71:
34:
32:
27:
1487:spin states
491:aluminoxane
123:nickelocene
115:cobaltocene
1719:Categories
1435:Principles
1017:amino acid
934:Si donors:
505:References
107:chromocene
76:pentahapto
1686:chemistry
1506:Reactions
1482:Hapticity
1266:S donors:
1107:O donors:
1080:P donors:
1042:porphyrin
989:imidazole
966:N donors:
762:C donors:
731:B donors:
707:H donors:
618:229180362
602:0002-7863
414:include C
178:(CpMn(CO)
149:catalysts
99:ferrocene
610:33315367
156:Fp dimer
142:ethylene
131:sandwich
86:Examples
880:& C
279:ligands
134:complex
121:), and
788:ďźCH-CH
616:
608:
600:
526:
438:-Bu).
216:Fe(CO)
206:Ď bond
779:HC(O)
774:RC(O)
614:S2CID
578:(PDF)
434:(R =
158:, (Cp
125:(NiCp
117:(CoCp
109:(CrCp
101:(FeCp
43:metal
41:of a
37:is a
1182:acac
1154:/HCO
1037:bipy
796:C(CH
606:PMID
598:ISSN
524:ISBN
480:ZrCl
474:and
469:TiCl
436:tert
275:base
166:(CO)
45:and
26:, a
1277:NCS
1254:OPR
1230:OSR
1209:ClO
1196:ONO
1174:RCO
1051:Si)
1047:(Me
1032:RCN
999:RNO
947:4ân
945:SiR
901:âĄCR
893:=CR
888:RNC
812:ďźCH
658:doi
590:doi
586:142
334:An
182:).
113:),
91:Bis
1721::
1381:Br
1376:Cl
1344:NC
1335:SR
1315:SO
1285:RS
1246:PO
1238:SO
1225:NO
1201:NO
1191:CO
1150:CO
1132:RO
1095:PR
1087:PR
1071:CS
1027:RN
1012:py
1004:NO
994:NO
973:NH
957:Si
882:70
878:60
851:CO
846:CO
841:CN
820:RC
808:CH
784:CH
738:BR
652:.
612:.
604:.
596:.
584:.
580:.
513:^
501:.
476:Cp
465:Cp
368:Fe
319:A
243:.
162:Fe
72:Cp
33:A
1420:e
1413:t
1406:v
1386:I
1370:2
1368:F
1363:F
1346:S
1339:O
1337:2
1329:3
1327:O
1325:2
1323:S
1317:2
1309:2
1307:S
1305:2
1303:C
1301:2
1299:R
1294:S
1292:2
1290:R
1279:2
1275:2
1273:R
1256:3
1248:4
1240:4
1232:2
1223:5
1221:H
1219:5
1217:C
1211:4
1203:3
1189:2
1187:R
1176:2
1168:4
1166:O
1164:2
1162:C
1156:3
1152:3
1144:2
1142:O
1137:O
1127:O
1125:2
1123:R
1118:O
1116:2
1114:H
1097:2
1089:3
1069:N
1062:2
1060:N
1055:N
1053:2
1049:3
1022:N
1006:2
983:3
981:N
975:3
955:3
953:R
943:n
941:H
924:7
922:H
920:9
918:C
912:5
910:H
908:5
906:C
895:2
876:C
870:6
868:R
866:6
864:C
859:C
853:2
835:4
833:H
831:6
829:C
824:R
822:2
814:2
810:2
802:3
800:)
798:2
790:2
786:2
769:R
752:n
750:H
748:m
746:B
740:2
721:2
719:H
714:H
692:e
685:t
678:v
664:.
660::
654:8
620:.
592::
482:2
478:2
471:2
467:2
432:2
430:H
428:3
426:R
424:5
420:4
418:R
416:5
374:2
372:N
370:2
366:2
364:)
362:2
360:H
358:5
356:C
354:3
233:Ρ
226:Ρ
222:Ρ
218:2
214:2
210:3
193:Ρ
180:3
168:4
164:2
160:2
127:2
119:2
111:2
103:2
80:Ρ
78:(
65:5
60:H
56:5
51:C
49:(
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