538:
565:
654:
20:
514:
596:
248:
627:
264:
426:
673:
217:. Animals and humans can obtain the necessary iron from foods that contain it in assimilable form, such as meat. Other organisms must obtain their iron from the environment. However, iron tends to form highly insoluble iron(III) oxides/hydroxides in aerobic (
465:
Iron(II) is a d center, meaning that the metal has six "valence" electrons in the 3d orbital shell. The number and type of ligands bound to iron(II) determine how these electrons arrange themselves. With so-called "strong field ligands" such as
433:
Iron(II) is found in many minerals and solids. Examples include the sulfide and oxide, FeS and FeO. These formulas are deceptively simple because these sulfides and oxides are often
244:
In contrast to iron(III) aquo complexes, iron(II) aquo complexes are soluble in water near neutral pH. Ferrous iron is however oxidized by the oxygen in air, converting to iron(III).
237:
that form soluble complexes with iron(III), that can be reabsorbed into the cell. (The other plants instead encourage the growth around their roots of certain bacteria that
756:
564:
595:
537:
626:
943:
844:
831:. Reference Module in Earth Systems and Environmental Sciences. Vol. 10 (Second ed.). Elsevier. pp. 437–473.
869:
791:
354:
of hydrogen peroxide to create two different oxygen-radical species, with water (H + OH) as a byproduct.
417:
generated by this process engage in secondary reactions, which can degrade many organic and biochemical compounds.
653:
126:, although more precise descriptions include other ligands such as water and halides. Iron(III) centres occur in
885:
Tang, Zhongmin; Zhao, Peiran; Wang, Han; Liu, Yanyan; Bu, Wenbo (2021). "Biomedicine Meets Fenton
Chemistry".
938:
672:
292:
757:"Iron integral to the development of life on Earth – and the possibility of life on other planets"
827:
Petsch, S.T. (2014). "10.11 - The Global Oxygen Cycle". In
Holland, H.D.; Turekian, K.K. (eds.).
711:
342:. Iron(III) is then reduced back to iron(II) by another molecule of hydrogen peroxide, forming a
150:
502:
is paramagnetic. It is high-spin. With chloride, iron(III) forms tetrahedral complexes, e.g.
760:
429:
Iron(II) oxide (ferrous oxide), FeO, is a very complicated material that contains iron(II).
127:
8:
299:
482:
has no unpaired electrons. It is low-spin. With so-called "weak field ligands" such as
910:
836:
351:
914:
902:
865:
840:
787:
434:
306:
272:
75:
806:
H. Marschner and V. Römheld (1994): "Strategies of plants for acquisition of iron".
894:
832:
811:
726:
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632:
543:
331:
251:
173:
115:
55:
48:
714: – Recyclable materials left over from manufactured products after their use
570:
339:
222:
185:
898:
19:
720:
705:
195:
517:
d-orbital splitting scheme for low- and high spin octahedral Fe(II) complexes.
107:
933:
927:
513:
437:. For example, "ferrous sulfide" can refer to the 1:1 species (mineral name
347:
335:
906:
708: – Mechanism by which materials form into and are attracted to magnets
487:
471:
449:("lode stone") is a mixed-valence compound with both Fe(II) and Fe(III), Fe
414:
343:
276:
247:
134:
736:
679:
636:
574:
234:
230:
97:
815:
442:
207:
203:
199:
601:
446:
327:
210:. In many of these proteins, Fe(II) converts reversibly to Fe(III)
154:
92:
40:
781:
663:
438:
310:
298:
The aquo ligands on iron(II) complexes are labile. It reacts with
226:
305:
When metallic iron (oxidation state 0) is placed in a solution of
263:
467:
425:
191:
146:
723: – Inorganic compound with the formula FeO (ferrous oxide)
702: – The element iron in its +3 oxidation state — compounds
699:
218:
214:
119:
87:
233:
can thrive in such environments by secreting compounds called
194:
in living beings contain iron(III) centers. Examples of such
483:
238:
131:
102:
859:
739: – Process for producing steel from iron ore and scrap
51:
716:
Pages displaying short descriptions of redirect targets
420:
731:
Pages displaying wikidata descriptions as a fallback
486:, the four of the six electrons are unpaired. Thus
925:
884:
864:(2nd ed.). Oxford: Butterworth-Heinemann.
782:Berg, Jeremy Mark; Lippard, Stephen J. (1994).
309:, iron(II) chloride is formed, with release of
258:
70:is often used to specify such compounds, as in
786:. Sausalito, Calif: University Science Books.
118:(salts), such an atom may occur as a separate
326:Iron(II) is oxidized by hydrogen peroxide to
241:iron(III) to the more soluble iron(II).)
213:Insufficient iron in the human diet causes
190:All known forms of life require iron. Many
149:ligands are bound the metal centre; or, in
95:salts, containing the cation Fe. The word
16:The element iron in its +2 oxidation state
441:) or a host of Fe-deficient derivatives (
512:
510:. Tetrahedral complexes are high spin.
424:
262:
246:
18:
860:Earnshaw, A.; Greenwood, N. N. (1997).
800:
926:
826:
810:, volume 165, issue 2, pages 261–274.
302:to give the blue iron(II) derivative:
179:
784:Principles of bioinorganic chemistry
384:
356:
271:Typically iron(II) salts, like the "
853:
604:, Ferrous phosphate octahydrate, Fe
470:, the six electrons pair up. Thus
176:anions are bound to the Fe centre.
13:
837:10.1016/B978-0-08-095975-7.00811-1
421:Iron(II) minerals and other solids
14:
955:
671:
652:
625:
594:
563:
536:
23:Iron(II) chloride tetrahydrate,
878:
820:
775:
749:
122:(positive ion) abbreviated as
1:
944:Chemical compounds by element
743:
221:) environment, especially in
633:Ferrous sulfate heptahydrate
338:in the process. This is the
259:Iron(II) salts and complexes
7:
899:10.1021/acs.chemrev.0c00977
693:
544:Ferrous nitrate hexahydrate
403:
375:
10:
960:
521:
460:
183:
862:Chemistry of the elements
729: – chemical compound
571:Ferrous oxalate dihydrate
528:Selected Fe(II) compounds
829:Treatise on Geochemistry
293:ferrous ammonium sulfate
151:organometallic compounds
712:Ferrous metal recycling
518:
430:
350:. The net effect is a
268:
255:
128:coordination complexes
106:
36:
516:
428:
313:gas, by the reaction
266:
250:
22:
761:University of Oxford
101:is derived from the
91:is used instead for
318:Fe + 2 H → Fe + H
300:1,10-phenanthroline
267:Redox reaction of .
180:Iron(II) in biology
939:Iron(II) compounds
816:10.1007/BF00008069
678:Ferrous silicate,
519:
431:
352:disproportionation
279:with the formulas
269:
256:
111:, meaning "iron".
37:
846:978-0-08-095975-7
763:. 7 December 2021
733:(ferrous bromide)
435:nonstoichiometric
411:
410:
383:
382:
307:hydrochloric acid
130:, such as in the
85:). The adjective
76:iron(II) chloride
951:
919:
918:
893:(4): 1981–2019.
887:Chemical Reviews
882:
876:
875:
857:
851:
850:
824:
818:
804:
798:
797:
779:
773:
772:
770:
768:
753:
732:
727:Iron(II) bromide
717:
675:
656:
629:
598:
567:
540:
509:
501:
481:
445:). The mineral
405:
385:
377:
357:
332:hydroxyl radical
322:
290:
252:Pourbaix diagram
223:calcareous soils
174:cyclopentadienyl
171:
144:
84:
72:ferrous chloride
58:. The adjective
34:
959:
958:
954:
953:
952:
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949:
948:
924:
923:
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879:
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660:Ferrous sulfide
657:
648:
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621:
619:
615:
611:
607:
599:
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588:
584:
580:
568:
559:
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541:
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367:
363:
340:Fenton reaction
321:
317:
288:
284:
280:
261:
254:of aqueous iron
196:metalloproteins
188:
186:Iron metabolism
182:
169:
165:
161:
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142:
138:
116:ionic compounds
83:
79:
56:oxidation state
32:
28:
24:
17:
12:
11:
5:
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808:Plant and Soil
799:
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747:
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742:
741:
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734:
724:
721:Iron(II) oxide
718:
709:
706:Ferromagnetism
703:
695:
692:
688:
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683:
677:
670:
668:
658:
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593:
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582:
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569:
562:
560:
555:
551:
547:
542:
535:
532:
531:
527:
526:
525:
523:
520:
505:
497:
493:
477:
462:
459:
454:
450:
422:
419:
409:
408:
399:
397:
396:→ Fe + HOO + H
393:
389:
381:
380:
371:
369:
368:→ Fe + HO + OH
365:
361:
346:radical and a
324:
323:
319:
291:, as found in
286:
282:
277:aquo complexes
260:
257:
184:Main article:
181:
178:
167:
163:
159:
153:, such as the
140:
81:
64:or the prefix
47:refers to the
30:
26:
15:
9:
6:
4:
3:
2:
956:
945:
942:
940:
937:
935:
932:
931:
929:
916:
912:
908:
904:
900:
896:
892:
888:
881:
873:
871:0-7506-3365-4
867:
863:
856:
848:
842:
838:
834:
830:
823:
817:
813:
809:
803:
795:
793:0-935702-73-3
789:
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762:
758:
752:
748:
738:
735:
728:
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722:
719:
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681:
674:
669:
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661:
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638:
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628:
623:
603:
597:
592:
576:
572:
566:
561:
545:
539:
534:
533:
515:
511:
489:
485:
473:
469:
458:
448:
444:
440:
436:
427:
418:
416:
415:free radicals
407:
400:
398:
387:
386:
379:
372:
370:
359:
358:
355:
353:
349:
345:
341:
337:
336:hydroxide ion
333:
329:
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296:
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50:
46:
42:
21:
890:
886:
880:
861:
855:
828:
822:
807:
802:
783:
777:
765:. Retrieved
751:
488:aquo complex
472:ferrocyanide
464:
432:
412:
401:
373:
344:hydroperoxyl
330:, forming a
325:
304:
297:
270:
243:
235:siderophores
212:
189:
172:, where two
145:, where six
135:ferrocyanide
123:
113:
96:
86:
71:
66:
65:
60:
59:
44:
38:
737:Steelmaking
680:Ferrosilite
637:Melanterite
575:Humboldtine
476:[Fe(CN)
208:cytochromes
139:[Fe(CN)
928:Categories
744:References
443:pyrrhotite
219:oxygenated
206:, and the
204:ferredoxin
200:hemoglobin
54:in its +2
915:231712587
602:Vivianite
504:[FeCl
492:[Fe(H
447:magnetite
328:iron(III)
281:[Fe(H
158:[Fe(C
155:ferrocene
93:iron(III)
41:chemistry
907:33492935
694:See also
664:Troilite
439:troilite
311:hydrogen
273:chloride
227:Bacteria
198:include
192:proteins
45:iron(II)
29:·4H
682:, FeSiO
546:, Fe(NO
522:Gallery
468:cyanide
461:Bonding
231:grasses
147:cyanide
98:ferrous
61:ferrous
49:element
913:
905:
868:
843:
790:
700:Ferric
639:, FeSO
388:Fe + H
360:Fe + H
348:proton
334:and a
275:" are
239:reduce
215:anemia
120:cation
108:ferrum
88:ferric
67:ferro-
911:S2CID
767:9 May
666:, FeS
577:, FeC
484:water
132:anion
105:word
103:Latin
934:Iron
903:PMID
866:ISBN
841:ISBN
788:ISBN
769:2022
413:The
229:and
80:FeCl
74:for
52:iron
25:FeCl
895:doi
891:121
833:doi
812:doi
643:·7H
616:·8H
608:(PO
585:·2H
554:·6H
295:.
114:In
39:In
930::
909:.
901:.
889:.
839:.
759:.
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496:O)
457:.
285:O)
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124:Fe
43:,
917:.
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849:.
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796:.
771:.
684:3
647:O
645:2
641:4
620:O
618:2
614:2
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610:4
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589:O
587:2
583:4
581:O
579:2
558:O
556:2
552:2
550:)
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508:]
506:4
500:]
498:6
494:2
490:(
480:]
478:6
474:(
455:4
453:O
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404:2
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394:2
392:O
390:2
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376:1
374:(
366:2
364:O
362:2
320:2
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287:6
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170:]
168:2
166:)
164:5
162:H
160:2
143:]
141:6
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31:2
27:2
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