25:
82:
349:
298:
310:
238:
complexes. It was soon understood by many organometallic chemists that a Cp ligand is isolobal to Tp. As many insights into chemistry can be obtained by the study of a series of closely related compounds (where only one feature is changed) a great deal of organometallic chemistry has been done using
534:
to form a ligand which can bind with three oxygens and three nitrogens to a metal. Trispyrazolylmethane (Tpm) is another class of scorpionate ligands, notable for having identical geometry and very similar coordination chemistry to Tp with only a difference in charge between them. Another variation
542:
Hydrotris(pyrazolyl)aluminate (Tpa) complexes have similar coordination geometries to Tp complexes, however Tpa ligands are more reactive due to the weaker Al-N and Al-H bonds, compared to B-N and B-H bonds of Tp ligands, which results in either Tpa ligand transfer, pyrazolate transfer, or hydride
382:
is evolved as the borohydride is sequentially converted first to pyrazolylborate , then to bis(pyrazolyl)borate , and finally to tris(pyrazolyl)borate . Bulky pyrazolyl borates can be prepared from 3,5-disubstituted pyrazoles, such as the dimethyl derivative. These bulky pyrazolyl borates have
366:
The tris(pyrazolyl)borate ligand is often known as Tp to many inorganic chemists - using different pyrazoles substituted in the 3,4, and 5 positions, a range of different ligands can be formed. In this article we will group all the trispyrazolylborates together.
289:, with one face of the Cp ligand binding to the metal atom. The tricarbonyl manganese complex of trithia-9-crown-3 has the three sulfur atoms binding to the metal atom in the same place as the Cp ligand and using the same sort of orbitals for the bonding.
149:
While many scorpionate ligands are of the Tp class, many other scorpionate ligands are known. For example, the Tm and tripodal phosphine classes have an equally good claim to be scorpionate ligands. Many of the scorpionate ligands have a central
146:; the third and final donor site reaches over the plane formed by the metal and the other two donor atoms to bind to the metal. The binding can be thought of as being like a scorpion grabbing the metal with two pincers before stinging it.
383:
proven especially valuable in the preparation of catalysts and models for enzyme active sites. Utilizing scorpionate ligands in the syntheses of metal catalysts may allow simpler and more accurate methods to be developed.
641:
Hammes BS, Chohan BS, Hoffman JT, Einwächter S, Carrano CJ (November 2004). "A family of dioxo-molybdenum(VI) complexes of N2X heteroscorpionate ligands of relevance to molybdoenzymes".
166:. Since this work a range of ligands have been reported where more than one type of metal binding group is attached to the central atom; these are the heteroscorpionates.
258:) ligands related ligands and form related complexes. These ligands donate the same number of electrons to the metal, and the donor atoms are arranged in a
126:
735:
391:
between the nitrogens and the metal stabilize the metal; these attributes help scorpionate compounds with creating highly symmetrical
139:
chemist of
Ukrainian descent, Swiatoslaw Trofimenko. Trofimenko called this discovery "a new and fertile field of remarkable scope".
821:
135:
ligands. These were also the first to become popular. These ligands first appeared in journals in 1966 from the then little-known
326:
complexes with the metals, the geometry of the Tm ligands (and sometimes their bidentate versions Bm) are such that with late
613:
694:
142:
The term scorpionate comes from the fact that the ligand can bind a metal with two donor sites like the pincers of a
68:
46:
162:
Trofimenko's initial work in the field was with the homoscorpionates where three pyrazolyl groups are attached to a
39:
851:
888:
868:
628:
831:
811:
791:
781:
154:
atom which bears a total of four groups, but it is possible to create ligands which use other central atoms.
707:
D.L. Reger (1999). "Tris(Pyrazolyl)Methane
Ligands: The Neutral Analogs of Tris(Pyrazolyl)Borate Ligands".
169:
Many other chemists continue to explore the possibilities of scorpionate ligand alternatives, such as:
213:
for very different applications, "heteroscorpionate ligands" have been examined of hybrid scorpionate/
893:
370:
These compounds are usually synthesized by reacting pyrazole with alkali-metal borohydrides, such as
392:
251:
235:
214:
33:
527:
207:
286:
110:
50:
334:
it is possible to turn the Tm ligand inside out to form a borane to which the metal forms a
872:
536:
8:
371:
274:
227:
131:
manner. The most popular class of scorpionates are the hydrotris(pyrazolyl)borates or
755:
690:
658:
609:
578:
801:
747:
716:
650:
586:
327:
841:
531:
433:
102:
203:
Sulfur donor groups such as those found in the Tm ligand or oxygen donor groups.
556:
399:
720:
882:
759:
662:
676:
322:
While the geometry of the Tp ligands do not allow the formation of simple
441:
335:
247:
590:
436:'s group have been working on this ligand class. To form NaTm {Na HB(mt)
736:"Poly(pyrazolyl)aluminate complexes containing aluminum-hydrogen bonds"
606:
Scorpionates: The
Coordination Chemistry Of Polypyrazolylborate Ligands
460:
411:
388:
361:
267:
118:
751:
654:
479:
448:
417:
282:
231:
178:
86:
464:
429:
331:
143:
98:
90:
81:
348:
297:
217:-lithium compounds such as which catalyzes olefin polymerization.
452:
174:
476:
456:
421:
396:
384:
323:
243:
189:
182:
136:
122:
309:
640:
163:
151:
94:
263:
157:
89:
complex of a homoscorpionate, the organic ligand has four
387:
allow for good shielding of the bound metal while strong
16:
Tridentate ligand which "pinches" the central metal atom
239:
Tp (and more recently Tm) as a co-ligand on the metal.
603:
402:(with the compound hydrotris(pyrazolyl) borate Mn).
97:. The other three ligands attached to the metal are
576:S. Trofimenko (1966). "Boron-Pyrazole Chemistry".
880:
733:
677:"People | ANU Research School of Chemistry"
597:
858:, part 9 (2013) special issue on scorpionates.
734:Snyder CJ, Heeg MJ, Winter CH (October 2011).
547:(M = Mg, Mn, Fe, Co, Ni, Cu, Zn; X = Cl, Br).
575:
444:and sodium borohydride are heated together.
727:
634:
706:
341:Here is the manganese complex of Tm with (
206:changing the ligands to alter the type of
185:compounds in place of the pyrazole rings²;
69:Learn how and when to remove this message
822:Journal of the American Chemical Society
80:
32:This article includes a list of general
315:Trithia-9-crown-3 manganese tricarbonyl
234:a vast amount of work has been done on
158:Homoscorpionates vs. heteroscorpionates
881:
467:, and other metals has been reported.
432:.Âą; Several research groups including
428:can be made. These are related to the
303:Cyclopentadienyl manganese tricarbonyl
526:have been reviewed. The tetra amine (
416:By replacing the nitrogen donor of a
604:Trofimenko Swiatoslaw (1999-08-16).
18:
424:atoms, a class of ligands known as
13:
770:
347:
125:that binds to a central atom in a
38:it lacks sufficient corresponding
14:
905:
873:Pinch and Sting: The Scorpionates
862:
242:The Tp, Tm, trithia-9-crown-3 (a
852:Acta Crystallographica Section C
308:
296:
23:
869:Chemical & Engineering News
776:Examples of Scorpionate ligands
629:Chemical & Engineering News
700:
683:
669:
622:
569:
221:
192:heptadentate ligands such as N
1:
562:
281:ligands. For example, the Cp
447:Coordination chemistry with
7:
550:
537:Trisoxazolinylborate ligand
405:
355:
200:from the ligand trisamineÂł;
10:
910:
409:
359:
273:The Tp and Tm ligands are
721:10.1080/02603599908020413
285:tricarbonyl complex is a
470:
631:, Aug. 28 1967, pg. 72.
528:tris(2-aminoethyl)amine
208:molecular encapsulation
53:more precise citations.
889:Coordination chemistry
689:Cotton and Wilkinson (
530:) can be reacted with
352:
287:half sandwich compound
111:coordination chemistry
106:
697:, 5th Ed) on page 436
395:silver complexes and
351:
343:again three carbonyls
93:groups attached to a
84:
608:. World Scientific.
832:Inorganic Chemistry
812:Inorganic Chemistry
792:Inorganic Chemistry
782:Inorganic Chemistry
591:10.1021/ja00960a065
330:such as osmium and
246:version of a small
188:the possibility of
121:(three-donor-site)
378:, under reflux. H
372:sodium borohydride
353:
262:manner covering a
226:Since the work by
115:scorpionate ligand
107:
875:, April 28, 2003.
752:10.1021/ic201541c
709:Comm. Inorg. Chem
655:10.1021/ic049130p
615:978-1-78326-199-4
579:J. Am. Chem. Soc.
328:transition metals
210:needed to metals;
79:
78:
71:
901:
894:Tripodal ligands
818:(24), 7978-7989.
802:Chemical Reviews
798:(26), 8212-8214.
788:(24), 7800–7806.
764:
763:
731:
725:
724:
704:
698:
687:
681:
680:
673:
667:
666:
638:
632:
626:
620:
619:
601:
595:
594:
585:(8): 1842–1844.
573:
543:transfer with MX
312:
300:
252:cyclopentadienyl
236:cyclopentadienyl
215:cyclopentadienyl
85:An example of a
74:
67:
63:
60:
54:
49:this article by
40:inline citations
27:
26:
19:
909:
908:
904:
903:
902:
900:
899:
898:
879:
878:
865:
842:Organometallics
773:
771:Further reading
768:
767:
746:(19): 9210–12.
732:
728:
705:
701:
688:
684:
675:
674:
670:
639:
635:
627:
623:
616:
602:
598:
574:
570:
565:
553:
546:
532:salicylaldehyde
525:
521:
517:
513:
509:
505:
501:
497:
493:
489:
485:
473:
439:
434:Anthony F. Hill
414:
408:
381:
377:
364:
358:
320:
319:
318:
317:
316:
313:
305:
304:
301:
224:
199:
195:
160:
103:carbon monoxide
75:
64:
58:
55:
45:Please help to
44:
28:
24:
17:
12:
11:
5:
907:
897:
896:
891:
877:
876:
864:
863:External links
861:
860:
859:
849:
839:
829:
819:
809:
799:
789:
778:
777:
772:
769:
766:
765:
726:
699:
682:
668:
649:(24): 7800–6.
633:
621:
614:
596:
567:
566:
564:
561:
560:
559:
557:Pincer ligands
552:
549:
544:
523:
519:
515:
511:
507:
503:
499:
495:
491:
487:
483:
472:
469:
437:
410:Main article:
407:
404:
400:polymerization
393:supramolecular
379:
375:
360:Main article:
357:
354:
314:
307:
306:
302:
295:
294:
293:
292:
291:
230:and others on
223:
220:
219:
218:
211:
204:
201:
197:
193:
186:
159:
156:
77:
76:
31:
29:
22:
15:
9:
6:
4:
3:
2:
906:
895:
892:
890:
887:
886:
884:
874:
870:
867:
866:
857:
853:
850:
847:
843:
840:
838:(4), 846-848.
837:
833:
830:
827:
823:
820:
817:
813:
810:
807:
803:
800:
797:
793:
790:
787:
783:
780:
779:
775:
774:
761:
757:
753:
749:
745:
741:
737:
730:
722:
718:
715:(1–3): 1–28.
714:
710:
703:
696:
695:0-471-84997-9
692:
686:
678:
672:
664:
660:
656:
652:
648:
644:
637:
630:
625:
617:
611:
607:
600:
592:
588:
584:
581:
580:
572:
568:
558:
555:
554:
548:
540:
538:
533:
529:
482:such as HC(CH
481:
478:
468:
466:
462:
458:
454:
450:
445:
443:
435:
431:
427:
423:
419:
413:
403:
401:
398:
394:
390:
386:
373:
368:
363:
350:
346:
344:
339:
337:
333:
329:
325:
311:
299:
290:
288:
284:
280:
276:
271:
269:
265:
261:
257:
253:
249:
245:
240:
237:
233:
229:
216:
212:
209:
205:
202:
191:
187:
184:
180:
176:
172:
171:
170:
167:
165:
155:
153:
147:
145:
140:
138:
134:
130:
129:
124:
120:
116:
112:
104:
100:
96:
92:
88:
83:
73:
70:
62:
52:
48:
42:
41:
35:
30:
21:
20:
855:
848:, 1200-1202.
845:
835:
828:, 1330-1331.
825:
815:
808:, 1851-1896.
805:
795:
785:
743:
739:
729:
712:
708:
702:
685:
671:
646:
642:
636:
624:
605:
599:
582:
577:
571:
541:
474:
446:
425:
415:
369:
365:
342:
340:
321:
278:
272:
259:
255:
241:
225:
168:
161:
148:
141:
132:
127:
114:
108:
65:
56:
37:
475:A range of
442:Methimazole
420:atoms with
389:sigma bonds
336:dative bond
248:crown ether
222:Isolobality
51:introducing
883:Categories
740:Inorg Chem
643:Inorg Chem
563:References
480:phosphines
461:molybdenum
412:Tm ligands
362:Tp ligands
268:polyhedron
173:utilizing
119:tridentate
59:March 2023
34:references
449:ruthenium
430:thioureas
418:Tp ligand
283:manganese
277:with the
232:ferrocene
228:Wilkinson
179:imidazole
105:) ligands
87:manganese
760:21877698
663:15554645
551:See also
510:and P(CH
477:tripodal
465:tungsten
406:Tm class
356:Tp class
332:platinum
275:isolobal
190:tripodal
144:scorpion
99:carbonyl
91:pyrazole
535:is the
453:rhodium
385:Ligands
175:pyrrole
47:improve
758:
693:
661:
612:
494:, N(CH
457:osmium
422:sulfur
397:olefin
324:borane
250:) and
244:sulfur
183:indole
137:DuPont
123:ligand
36:, but
471:Other
266:of a
181:, or
164:boron
152:boron
117:is a
95:boron
756:PMID
691:ISBN
659:PMID
610:ISBN
374:NaBH
264:face
113:, a
826:126
806:102
748:doi
717:doi
651:doi
587:doi
518:PMe
502:PPh
440:),
345:).
260:fac
128:fac
109:In
885::
871:,
856:69
854:,
846:23
844:,
836:44
834:,
824:,
816:42
814:,
804:,
796:43
794:,
786:43
784:,
754:.
744:50
742:.
738:.
713:21
711:.
657:.
647:43
645:.
583:88
539:.
514:CH
498:CH
486:PR
463:,
459:,
455:,
451:,
426:Tm
338:.
279:Cp
270:.
256:Cp
177:,
133:Tp
762:.
750::
723:.
719::
679:.
665:.
653::
618:.
593:.
589::
545:2
524:3
522:)
520:2
516:2
512:2
508:3
506:)
504:2
500:2
496:2
492:3
490:)
488:2
484:2
438:3
380:2
376:4
254:(
198:3
196:O
194:4
101:(
72:)
66:(
61:)
57:(
43:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
