252:
54:
118:
17:
108:
Homoleptic octahedral complexes have been characterized by X-ray crystallography for the following dications: Fe, Co, Ni, Zn, Cd. Hexakis complexes of both Ru and Ru are also known. Cu, Pd, and Pt form homoleptic square planar complexes. Zn, although crystallized as the hexakis complex, more
631:
Banerjee, Rahul; Furukawa, Hiroyasu; Britt, David; Knobler, Carolyn; o'Keeffe, Michael; Yaghi, Omar M. (2009). "Control of Pore Size and
Functionality in Isoreticular Zeolitic Imidazolate Frameworks and their Carbon Dioxide Selective Capture Properties".
170:
are common binding sites for metal ions. Unlike the free amino acid, the histidine residue (i.e., as a component of a peptide or protein), coordinates solely via the imidazole substituent. Examples include
400:
Alberto, Roger; Schibli, Roger; Waibel, Robert; Abram, Ulrich; Schubiger, August P. (1999). "Basic
Aqueous Chemistry of (M=Re, Tc) Directed Towards Radiopharmaceutical Application".
215:
Especially in cationic imidazole complexes, the N-H center is acidified. For tricationic d pentammines, deprotonation of the imidazole ligand gives imidazolate complexes with pK
556:"Metal Complexes with Mixed Ligands. 2. Molecular and Crystal Structure of Catena-di-mu-perchlorato[di-mu-imidazolato-diperchlorato-octa-imidazolo-tricopper(II)]; Cu
423:
Carver, Graham; Tregenna-Piggott, Philip L. W.; Barra, Anne-Laure; Neels, Antonia; Stride, John A. (2003). "Spectroscopic and
Structural Characterization of the Cation".
98:
in metal-imidazole complexes, a property that can be attributed to the presence of the pi-donor pyrrole-like NH center. For this reason, imidazole can be classified as
71:
nitrogen (HC=N-CH) of imidazole is basic, and it is this nitrogen that binds to metal ions. The pyrrole-like nitrogen ((HC-NH-CH) projects away from the metal. The pK
105:
Imidazole is a compact, flat ligand. Six imidazole ligands fit comfortably around octahedral metal centers, e.g., . The M-N(imidazole) bond is freely rotating.
1143:
373:
Sundberg, Richard J.; Bryan, Robert F.; Taylor, Ivan F.; Taube, Henry (1974). "Nitrogen-Bound and Carbon-Bound
Imidazole Complexes of Ruthenium Ammines".
1180:
207:) residues that is attached to proteins to facilitate purification. The concept relies on the affinity of the imidazole side chain for metal cations.
1356:
1030:
684:
331:
1374:
1210:
1379:
1247:
485:
Ashby, Carol I. H.; Cheng, C. P.; Brown, Theodore L. (1978). "Nitrogen-14 Nuclear
Quadrupole Resonance Spectra of Coordinated Imidazole".
132:
is slightly more basic than imidazole but is otherwise similar, if more lipophilic. Many salts of are known (R = alkyl, vinyl, etc.).
1266:
184:
1337:
1061:
997:
1202:
1010:
881:
156:
458:
Bonomo, Raffaele P.; Riggi, Francesco; Di Bilio, Angel J. (1988). "EPR Reinvestigation of the Copper(II)-Imidazole System".
1316:
1167:
1088:
1035:
677:
136:
are somewhat bulky ligands owing to the steric clash between the 2-methyl group and other ligands in octahedral complexes.
299:
1400:
1053:
1005:
263:
of imidazole (to give imidazolate) is 14, thus it is easy to deprotonate. Many metal complexes feature imidazolate as a
1328:
1283:
1239:
1223:
1025:
992:
869:
354:
159:. In common with other 3-substituted imidazoles, histidine can coordinate to metals via either of two nonequivalent
1369:
1278:
1135:
934:
91:= 9,24 of ammonium). The donor properties of imidazole are also indicated by the redox properties of its complexes.
39:. Complexes of imidazole itself are of little practical importance. In contrast, imidazole derivatives, especially
1231:
1194:
1189:
1155:
946:
911:
894:
886:
822:
762:
1040:
813:
801:
772:
767:
670:
57:
A "picket-fence porphyrin" complex of Fe, with axial coordination sites occupied by methylimidazole (green) and
1116:
1020:
974:
857:
777:
731:
279:
789:
163:. The free amino acid can coordinate through the imidazole and either or both of the carboxylate and amine.
267:. One example of an imidazolate complex from biochemistry is found at the active site of copper-containing
1308:
1130:
844:
231:
of 8.9. Thus, complexation to tricationic complexes acidify the pyrrolic NH center by at least 10,000.
1292:
852:
707:
300:"Structural Studies of Bis(histidinato)nickel(II): Combined Experimental and Computational Studies"
1080:
102:
ligand. Nonetheless, complexes between low-valent metals and imidazole are well known, e.g., .
1175:
987:
235:
1015:
554:
Ivarsson, Gun; Lundberg, Bruno K. S.; Ingri, Nils; Tricker, M. J.; Svensson, Sigfrid (1972).
325:
79:
cation is about 6.95, which indicates that the basicity of imidazole is intermediate between
966:
693:
268:
29:
8:
1361:
1107:
712:
176:
409:
297:
649:
440:
350:
188:
133:
129:
616:
555:
641:
611:
536:
494:
467:
432:
405:
382:
311:
515:
Hoq, M. Fazlul; Shepherd, Rex E. (1984). "Influence of the Metal
Centers on the p
264:
1125:
839:
316:
95:
1394:
834:
739:
140:
53:
653:
444:
899:
662:
144:
122:
99:
76:
540:
498:
471:
386:
251:
192:
645:
436:
200:
172:
160:
117:
43:, are pervasive ligands in biology where they bind metal cofactors.
40:
33:
80:
58:
94:
Imidazole is a pure sigma-donor ligand. There is no evidence for
196:
167:
422:
298:
A. Abbasi, B. Safarkoopayeh, N. Khosravi, A. Shayesteh (2017).
180:
36:
68:
630:
553:
399:
16:
372:
255:
Structure of am imidazolate-bridged tricopper complex.
112:
61:. This synthetic complex mimics aspects of myoglobin.
519:
of the
Pyrrole Hydrogen of Imidazole Complexes of (NH
278:(ΞΌ-imidazolate) motif underpins materials comprising
155:
Histidine complexes comprise an important subset of
457:
345:Lippard, Stephen J.; Berg, Jeremy M., eds. (1994).
166:The imidazole side chain of histidine residues in
349:. Mill Valley, Calif.: University Science Books.
210:
1392:
527:, M(III) = Co(III), Rh(III), Ir(III), Ru(III)".
484:
125:, illustrating the dimethylbenzimidazole ligand
678:
330:: CS1 maint: multiple names: authors list (
514:
344:
692:
685:
671:
185:alpha-ketoglutarate-dependent hydroxylases
615:
315:
634:Journal of the American Chemical Society
487:Journal of the American Chemical Society
375:Journal of the American Chemical Society
250:
246:
227:The d complex is more acidic, with a pK
116:
52:
46:
15:
368:
366:
109:typically forms a tetrahedral complex.
1393:
238:. This conversion has been observed:
666:
510:
508:
157:transition metal amino acid complexes
87:of pyridinium = 5.23) and ammonia (pK
363:
347:Principles of Bioinorganic Chemistry
20:Structure of the histidine complex .
338:
143:ligand is found in all versions of
113:Complexes of substituted imidazoles
13:
505:
26:transition metal imidazole complex
14:
1412:
234:Imidazole ligands are isomers of
624:
617:10.3891/acta.chem.scand.26-3005
280:zeolitic imidazolate frameworks
547:
478:
451:
416:
402:Coordination Chemistry Reviews
393:
291:
211:Reactions of imidazole ligands
1:
410:10.1016/S0010-8545(99)00128-9
285:
150:
7:
10:
1417:
1401:Transition metal compounds
317:10.1016/j.crci.2016.12.006
219:near 10 (M = Co, Rh, Ir):
1349:
1259:
1100:
1073:
959:
927:
755:
724:
700:
604:Acta Chemica Scandinavica
236:N-heterocyclic carbenes
694:Coordination complexes
256:
199:consisting of several
126:
62:
21:
304:Comptes Rendus Chimie
254:
247:Imidazolate complexes
120:
56:
47:Bonding and structure
32:that has one or more
19:
404:. 190β192: 901β919.
269:superoxide dismutase
30:coordination complex
541:10.1021/ic00181a015
529:Inorganic Chemistry
499:10.1021/ja00487a014
472:10.1021/ic00287a027
460:Inorganic Chemistry
425:Inorganic Chemistry
387:10.1021/ja00809a011
257:
191:("his tag") is an
177:carbonic anhydrase
134:2-Methylimidazoles
127:
63:
22:
1388:
1387:
646:10.1021/ja809459e
640:(11): 3875β3877.
535:(13): 1851β1858.
493:(19): 6057β6063.
466:(14): 2510β2512.
437:10.1021/ic034110t
431:(18): 5771β5777.
189:Polyhistidine-tag
130:N-methylimidazole
1408:
687:
680:
673:
664:
663:
658:
657:
628:
622:
621:
619:
551:
545:
544:
512:
503:
502:
482:
476:
475:
455:
449:
448:
420:
414:
413:
397:
391:
390:
370:
361:
360:
342:
336:
335:
329:
321:
319:
295:
1416:
1415:
1411:
1410:
1409:
1407:
1406:
1405:
1391:
1390:
1389:
1384:
1365:
1345:
1332:
1324:
1320:
1312:
1304:
1300:
1296:
1287:
1274:
1270:
1255:
1251:
1243:
1235:
1227:
1218:
1214:
1206:
1198:
1184:
1171:
1163:
1159:
1151:
1147:
1139:
1120:
1111:
1096:
1092:
1084:
1069:
1057:
1048:
1044:
1001:
978:
970:
955:
950:
942:
938:
923:
919:
915:
907:
903:
890:
877:
873:
865:
861:
848:
830:
826:
817:
809:
805:
797:
793:
785:
781:
751:
747:
743:
735:
720:
716:
696:
691:
661:
629:
625:
599:
595:
591:
587:
583:
579:
575:
571:
567:
563:
559:
552:
548:
526:
522:
513:
506:
483:
479:
456:
452:
421:
417:
398:
394:
371:
364:
357:
343:
339:
323:
322:
296:
292:
288:
277:
265:bridging ligand
262:
249:
230:
218:
213:
153:
115:
90:
86:
74:
49:
12:
11:
5:
1414:
1404:
1403:
1386:
1385:
1383:
1382:
1377:
1372:
1367:
1363:
1359:
1353:
1351:
1350:Halide donors:
1347:
1346:
1344:
1343:
1335:
1330:
1326:
1322:
1318:
1314:
1310:
1306:
1302:
1298:
1294:
1290:
1285:
1281:
1276:
1272:
1268:
1263:
1261:
1257:
1256:
1254:
1253:
1249:
1245:
1241:
1237:
1233:
1229:
1225:
1221:
1216:
1212:
1208:
1204:
1200:
1196:
1192:
1187:
1182:
1178:
1173:
1169:
1165:
1161:
1157:
1153:
1149:
1145:
1141:
1137:
1133:
1128:
1123:
1118:
1114:
1109:
1104:
1102:
1098:
1097:
1095:
1094:
1090:
1086:
1082:
1077:
1075:
1071:
1070:
1068:
1067:
1059:
1055:
1051:
1046:
1042:
1038:
1033:
1028:
1023:
1018:
1013:
1008:
1003:
999:
995:
990:
985:
980:
976:
972:
968:
963:
961:
957:
956:
954:
953:
948:
944:
940:
936:
931:
929:
925:
924:
922:
921:
917:
913:
909:
905:
901:
897:
892:
888:
884:
879:
875:
871:
867:
863:
859:
855:
850:
846:
842:
837:
832:
828:
824:
820:
815:
811:
807:
803:
799:
795:
791:
787:
783:
779:
775:
770:
765:
759:
757:
753:
752:
750:
749:
745:
741:
737:
733:
728:
726:
722:
721:
719:
718:
714:
710:
704:
702:
698:
697:
690:
689:
682:
675:
667:
660:
659:
623:
597:
593:
589:
585:
581:
577:
573:
569:
565:
561:
557:
546:
524:
520:
504:
477:
450:
415:
392:
381:(2): 381β392.
362:
356:978-0935702729
355:
337:
289:
287:
284:
275:
260:
248:
245:
244:
243:
228:
225:
224:
216:
212:
209:
152:
149:
114:
111:
96:pi backbonding
88:
84:
75:of protonated
72:
65:
64:
48:
45:
9:
6:
4:
3:
2:
1413:
1402:
1399:
1398:
1396:
1381:
1378:
1376:
1373:
1371:
1368:
1366:
1360:
1358:
1355:
1354:
1352:
1348:
1342:
1341:
1336:
1334:
1327:
1325:
1315:
1313:
1307:
1305:
1291:
1289:
1282:
1280:
1277:
1275:
1265:
1264:
1262:
1258:
1252:
1246:
1244:
1238:
1236:
1230:
1228:
1222:
1220:
1209:
1207:
1201:
1199:
1193:
1191:
1188:
1186:
1179:
1177:
1174:
1172:
1166:
1164:
1154:
1152:
1142:
1140:
1134:
1132:
1129:
1127:
1124:
1122:
1115:
1113:
1106:
1105:
1103:
1099:
1093:
1087:
1085:
1079:
1078:
1076:
1072:
1066:
1064:
1060:
1058:
1052:
1050:
1039:
1037:
1034:
1032:
1029:
1027:
1024:
1022:
1019:
1017:
1014:
1012:
1009:
1007:
1004:
1002:
996:
994:
991:
989:
986:
984:
981:
979:
973:
971:
965:
964:
962:
958:
952:
945:
943:
933:
932:
930:
926:
920:
910:
908:
898:
896:
893:
891:
885:
883:
880:
878:
868:
866:
856:
854:
851:
849:
843:
841:
838:
836:
833:
831:
821:
819:
812:
810:
800:
798:
788:
786:
776:
774:
771:
769:
766:
764:
761:
760:
758:
754:
748:
738:
736:
730:
729:
727:
723:
717:
711:
709:
706:
705:
703:
699:
695:
688:
683:
681:
676:
674:
669:
668:
665:
655:
651:
647:
643:
639:
635:
627:
618:
613:
610:: 3005β3020.
609:
605:
601:
550:
542:
538:
534:
530:
518:
511:
509:
500:
496:
492:
488:
481:
473:
469:
465:
461:
454:
446:
442:
438:
434:
430:
426:
419:
411:
407:
403:
396:
388:
384:
380:
376:
369:
367:
358:
352:
348:
341:
333:
327:
318:
313:
309:
305:
301:
294:
290:
283:
281:
272:
270:
266:
253:
241:
240:
239:
237:
232:
222:
221:
220:
208:
206:
202:
198:
194:
190:
186:
182:
178:
174:
169:
164:
162:
158:
148:
146:
142:
141:benzimidazole
137:
135:
131:
124:
121:Structure of
119:
110:
106:
103:
101:
97:
92:
82:
78:
70:
60:
55:
51:
50:
44:
42:
38:
35:
31:
27:
18:
1339:
1062:
982:
637:
633:
626:
607:
603:
549:
532:
528:
516:
490:
486:
480:
463:
459:
453:
428:
424:
418:
401:
395:
378:
374:
346:
340:
326:cite journal
307:
303:
293:
273:
258:
233:
226:
214:
204:
165:
154:
138:
128:
107:
104:
93:
66:
25:
23:
145:vitamin B12
139:A modified
123:vitamin b12
77:imidazolium
1011:amino acid
928:Si donors:
310:(5): 467.
286:References
282:("ZIF"s).
193:amino acid
183:(Cu), and
1260:S donors:
1101:O donors:
1074:P donors:
1036:porphyrin
983:imidazole
960:N donors:
756:C donors:
725:B donors:
701:H donors:
201:histidine
195:motif in
173:myoglobin
161:tautomers
151:Histidine
67:Only the
41:histidine
34:imidazole
1395:Category
654:19292488
445:12950228
223:β + H
197:proteins
168:proteins
81:pyridine
59:dioxygen
874:& C
37:ligands
782:οΌCH-CH
652:
443:
353:
259:The pK
187:(Fe).
181:azurin
179:(Zn),
175:(Fe),
773:HC(O)
768:RC(O)
274:The M
69:imine
28:is a
1176:acac
1148:/HCO
1031:bipy
790:C(CH
650:PMID
592:(ClO
441:PMID
351:ISBN
332:link
242:β
100:hard
1271:NCS
1248:OPR
1224:OSR
1203:ClO
1190:ONO
1168:RCO
1045:Si)
1041:(Me
1026:RCN
993:RNO
941:4βn
939:SiR
895:β‘CR
887:=CR
882:RNC
806:οΌCH
642:doi
638:131
612:doi
537:doi
495:doi
491:100
468:doi
433:doi
406:doi
383:doi
312:doi
205:His
83:(pK
1397::
1375:Br
1370:Cl
1338:NC
1329:SR
1309:SO
1279:RS
1240:PO
1232:SO
1219:NO
1195:NO
1185:CO
1144:CO
1126:RO
1089:PR
1081:PR
1065:CS
1021:RN
1006:py
998:NO
988:NO
967:NH
951:Si
876:70
872:60
845:CO
840:CO
835:CN
814:RC
802:CH
778:CH
732:BR
648:.
636:.
608:26
606:.
602:.
576:(C
560:(C
533:23
531:.
517:Ka
507:^
489:.
464:27
462:.
439:.
429:42
427:.
379:96
377:.
365:^
328:}}
324:{{
308:20
306:.
302:.
271:.
147:.
24:A
1380:I
1364:2
1362:F
1357:F
1340:S
1333:O
1331:2
1323:3
1321:O
1319:2
1317:S
1311:2
1303:2
1301:S
1299:2
1297:C
1295:2
1293:R
1288:S
1286:2
1284:R
1273:2
1269:2
1267:R
1250:3
1242:4
1234:4
1226:2
1217:5
1215:H
1213:5
1211:C
1205:4
1197:3
1183:2
1181:R
1170:2
1162:4
1160:O
1158:2
1156:C
1150:3
1146:3
1138:2
1136:O
1131:O
1121:O
1119:2
1117:R
1112:O
1110:2
1108:H
1091:2
1083:3
1063:N
1056:2
1054:N
1049:N
1047:2
1043:3
1016:N
1000:2
977:3
975:N
969:3
949:3
947:R
937:n
935:H
918:7
916:H
914:9
912:C
906:5
904:H
902:5
900:C
889:2
870:C
864:6
862:R
860:6
858:C
853:C
847:2
829:4
827:H
825:6
823:C
818:R
816:2
808:2
804:2
796:3
794:)
792:2
784:2
780:2
763:R
746:n
744:H
742:m
740:B
734:2
715:2
713:H
708:H
686:e
679:t
672:v
656:.
644::
620:.
614::
600:"
598:4
596:)
594:4
590:8
588:)
586:2
584:N
582:4
580:H
578:3
574:2
572:)
570:2
568:N
566:3
564:H
562:3
558:3
543:.
539::
525:5
523:)
521:3
501:.
497::
474:.
470::
447:.
435::
412:.
408::
389:.
385::
359:.
334:)
320:.
314::
276:2
261:a
229:a
217:a
203:(
89:a
85:a
73:a
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
