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Inorganic Chemistry [B.Sc.-I, , complexes are more stabl, , (Semester-I)) |, , than the complexes are formed, by the, ndentate ligand with the central metal atom or ion., mon Dimethyl glyoxime (dmg) also form chelating complex with, Np ion Fig, 24., CH, 0-H---0, , 117, , coordination of, ,CH3, , N, , N=, , C H - C = NOH, 2, , Ni, , Ni, , CH-C = NOH, , CH3, , Dimethyl glyoxime, , (DMG), , N:, , O, , H-0, , (Ni (DMG), , complex, , CH, , (chelate), , Fig., , 24: Formation, , The formation of,, , of chelate ring by |Wi(DMG), | 2 ion., , estimation, |Ni(dmg),|complexes, used for the, , of nickle, , in, , gravimetric, , analysis., , Factors, , affecting stability of chelate complexess, , the following factors., stability of chelate depends upon, such as ethylene diamine, The complex formed by chelating ligand, effect:, Chelate, (i), are more stable than, diamine tetraacetic acid (EDTA), and, ethylene, (acac"), acetylacetonato, en, ),, the m o n o dentate ligands such as NH,, the central metal atom or ion by, with, formed,, chelating, complex, stability of the complexes containing, and HO. Therefore, the enhanced, The, , chelate effect., is, ion with ethylene diamine (en), For example: The complex of Ni2*, , ligands is called, , corrosponding complex, , Ni2aq), , formed, , +, , more, , stable than the, , with, NH,, , 6NH,(aq), , log B, , Ni(NH12* (aq), , Nilaq)+3 en(aq)|Nilen),|*(ag) of the system., , logB, , During the, , 8.60, , =, , 18.30, , formation, , of, , increase the entropy, the moelcule, The formation of chelates, metal ion replaced with, of, shell, solvated, of water in the, cOmplexes, the molecules, increase in value of entropy., displaces the six, 01 hgands. As, a result there is, ammonia, molecules, 2, of, six, |Ni(NH,). 1 the, and out side the, molecules with in, For example : In complex,, of, number, in the, therefore, no change, of, water,, three, ecules, diamine. The, ethylene, with, coordination spheres., ion, or, of, , 1owever, complex, , formed, , of ethylene diamine, , Cle, system increases., Over,, , cannot get far, , other, , in, , by the, , interaction, , six, (en) displaces the, , multidenates, , ligand,, , one, , Ni2, , of water. As, , molecules, , result entropy, other, , end get, , (monodentate, , attached, , ligand), , attached to the metal atom or metal ion., , the, , also, , A, , aep, , stability, , the complexes, stability of, in Table-9, Table- 9., : The, complex, the greater, as, rings in a, , (ii) Number of Chelate rings, given, number of chelate, Dumber of, rings., The, The large the, constant of complexes, rings., c m p l e x e s ,, , comparison, , of the stability, , end, , the, with metal ion,, On the, ion is large., metal, to the, toget, ge, less chance, have, would, it, , attached, , it getting, the probability of, independent,, away and, are, , molecule, , of the com, , a

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Aii) Size of the chelate rings: The stability of metal, chelate depends upon the size, five membered ring are more stablè., of.aaUsually,, ring., o, dimethyl glyoxime and ethylene diamine form Chelating ligands such as oxalate i1on,, five-membered ring., However, acetylacetone form stable complex withstable, metal atom or ion. It is six membered, ring, , eomplex. The stability of complex is due to presence of unsaturation or double bond in the, , plexes. Acetylacetone, , from, , large number of complexes with metal atom, Ti(acac), ICr, IC{acac),| and [Colacac),l etc. Fig. 27, ITilacac),,, a, , comp, , or, , ion, such as,, , CHs, 0, , H-C, , M Where M =Ti, Cr, Co, , 0, CHs, Fig. 27: Ring forming ligand1, The ring of size, , greater than six, , are, , not very stable. The, , instability of higher, , membered, , due to., , ring are, electrostatic forces needed to bring the coordinating atom, i) Increase in work against, ion., together for bonding with metal atom or, formation of 7 or 8, concentration of other end of ligand for the, i) Decrease in effective, , membered ring., , ringg configuration., offer mutual repulsion, near the donor sites, , ii) Difficulty of finding stearically, (iv) The bulkier groups, , non, , crowded, , among theigands., , ooooooocOOOO00000000000c0OvOooOCooco0ocoooooo0ocoocoocoooooco0o0o%, , CHELATING, PROBELMS RELATED WITH, LIGANDS AND CHELATES, , 1., Ans., , What, , are, , chelates? Give, , one, , example., , Chelate: When a polydentate, ion forming, combines with a metal, For, , having more thanonecoordinating, chelate., ti. at is called as, complex,, ring type, , donor ie., , (where, example: Cu (en),1, , a, , en, , =, , a, , ethylene diamine), NH-CH, , HC- H,N, Cu, , HC, , H,N, , site,, , donor, , 12+, , NH-CH2, pair, , 2., , Ans., , ligand and, , itferentiate between, i) Ligand: It is defined, , of electrons to, , as a donor, , the metal (atom, , Forexample: NH, , HO:, , chelate., , (atom, anion, , or ion) forming, , a, , or, , which, molecule), , coordinate, , bond is, , lone pt, , donates, , calle, , igand.

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inorganic Chemistry [B.Sc.-Il, re of ethylene diamine tetra, acetate ion, , Structure of e, , (Semester-D)] |, , 121, , 00CH,C, , CHC00>, N-CH, CH2-N, 0OCHC, , CH,CO0>, , (Donar sites, , are, , indicated by arrows), , Structure of [Co (EDTAJ-, , O=CHC, , CH, N- CH2, , -0<, , o=C;-HC, , -CH2, , CH2, , NOMENCLATURE OF coORDINATIONS COMPOUNDS, Chemistry) system of, According to IUPAC (Internation Union of Pure and Applied, the following rules given as:, 2omenclature, of inorganic compounds,, cation (+ve ion), In ionic complex compound, the name of, 1. Order of naming ions.: G), anion (-ve ion) is written., mentioned first and then name of, , is sodium chloride, because in this inorganic, case of NaCi, its name, in, As, For example:, cation while Cl- ion is anion., compound Na* ions is, ionic compounds written:, Similarly n a m e complex, written first, the name of the cation, K* ion is, K,|P¢Ci,|,, (a) In complex compound, |PdCl,1is mentioned., then the n a m e of anion, , of, , cation, |Col(NH),|3*,is written, , |Co(lNHG),|Cl,,the name of, (b) In complexcompound, C is mentioned., first and then, , name, , of anion,, , compound, (i) If the complex, one, , is, , The, word for example., , non, , name, , tetracarbonylnicklet0)., , 2., , Naming of, , are named first then, , ionic, the, , name, , of complex, , written as, of complex compound, written as one word i.e.,, , |Na(CO),|is, , In naming the, coordination sphere:, , the, , name, , PECNH,)CII, the n a m e of NH, , coordination, , sphere, the ligands, , mentioned. For example, metal atom is, of central, followed the n a m e, is written first, , (ammine), , name ofcentral, and then the, chloro), Diamminedichloroplatinum (1I)., , 10n. The n a m e, metal atom or, , :, , In complex,, , ofother ligands, C, , of complex is, , |Pt(NH,),CI,|

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Inorganic Chemistry [B.Sc.-II (Semester-l)] | 123, (c) Naming of neutral ligands : The name of neutral ligands written as such, Table, , 11., , Table 11. Some neutral ligands, , Neutral ligands, , Name, , Neutral ligands, , Name, , cH)N, , Triethyl amine, , CH)P, , Triphenyl, phosphine, , Hydrazine, , CH CN, , Acetonitrile, , NH, CHNH,, , Methyl amine, , O,or :O=0:, , Dioxygen, , NH,OH, , Hydroxylamine, , (CH),NHH, , Dimethylamine, , PF, , CHN or py, , Pyridine, , (CHP, , NH-NH, or, , N,or N, , =N:, , Dinitrogen, Phosphorus, trifluoride, , Triethyl, phosphine, , However, there 'are few neutral ligands which are given special n a m e Table, Table 12. Special name of some ligands, , - 12., , Neutral ligands, , Name, , Neutral ligands, , Name, , CO, , Carbonyl, , NO, , Nitrosyl, , CS, , Thiocarbonyl, , NS, , Thionitrosyl, , HO, , Aquo or aqua, , NH, , Ammine, , According to latest system of nomenclature, the word "aqua" is used for H,O molecule., Note: The spelling of ammine with two m's. This is used only for NH, while other amines, are spelled with usual one m., d) Naming of free radicals: The free radical are given their own names Table - 13., , Table 13. Naming fo free radical., , Free radicals, , Name, , Free radicals, , Name, , H,C, , Methyl, , CH,, , Ethyl, , HC, , Phenyl, , 4. Order of naming ligands : The ligands should be named in alphabetical order, IDpective of their nature being negative, positive or neutral. F o r example : In tnec, , XCIXFXID), the ligands are named as bromo, chloro, fluoro and iodo., ed, . Numerical prefixes to indicate number ligands, indicated, number is, (i) 1 a, their, complex containse two or more simple ligands of same type,, prefvee such as Table 14., by putting prefixes

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ext BOOK Series, , Table 14. Prefixes, , Prefix, , No. of similar, , di, , for, , simple ligands, , ligands, , 2, , tri, , octa, , 5, , nona, , Hexa, , 6, , deca, , ligand, , 7, , hepta, , 3, , penta, , No. of similar, , Prefix, , 8, 9, , 10, , Ifthe complex contains two or more complex ligands 15., or organie molecules, their, heir umbeIndicated by putting the prefixes such as in Tabieligands, Table. 14. Prefixes for complex, , Prefix, , No. of similar ligands, , bis, , 2, , tris, , 3, , Prefix, , No. of similar ligands, 6, , hexakis, , 7, , heptakis, , tetrakis, 5, , pentakis, The, , name, , of complex, , ligand or organic molecule is, , written in brackett., , For example : The name of complex, | Co(NH,), (en), |* is written as diamminebi, , (ethylenediamine)cobalt (II) ion, 6., , Ending of names of name of central metal atom: The following two cases arises, , i, , (a) Ifcomplex ion is anionic in nature, the name of central metal atom endsinate, The name of some metals are given below Table - 16., Table 16. Name of metals in anionic complex ion., , Symbol for metal, , Name of metal, , Symbol for metal, , Name of metal, , Cu, , Cuperate, , Cd, , cadmate, , Cr, , Chromate, Cobaltate, , Zn, , Zincate, , Si, , Silicate, , Pd, , Palladate, , Ni, , Nicklate, , Os, , Osmate, , Al, , Aluminate, , mercurate, , B, , Borate, , Pt, , Platinate, , Co, , Hg, , For example: The name ofvuplex, |PtCi,|is written as Tetrachloroplatinate (I)o, the complex compound having the negatively charged coordination sphere is an, , () f, , acid the name ofmetal end in ic. For example: The name ofcomplex, H, | P:C\,, , hexachloroplatinic acid (IV)

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Inorganic Chemistry (B.Sc.-II (SemesterI)] |, (c), , 125, , Names of some metals are written in their latin form Table 17., Table 17. Latin name of some metal., , Symbol for metal, , Latin Name, , Fe, , Ferrate, , Ag, , Argentate, Aurate, , Au, , Plumbate, , Pb, , stannate, , Sn, , metal, n a m e of central, has positive charge or is neutral, the, the, compound, If, complex, 1s,, (d), n a m e of complex ion, |Cu(NH,),1, atom remain a s such. For example: The, is Tetracarbonylnickel 0)., Fetraamminecopper (II) ion and for [Ni(CO)], state of central metal, o r ion: The oxidation, atom, metal, central, of, state, 6.0xidation, bracket,, IV...... s o on in the, Romen numerals such as I, II, III,, , designated, , atom or ion, , is, , followed by, , the, , name, , by a, , of metal, , without a gap between, , : For examples, [Co(NH)CIICl: In, oxidation state, , are, , atom, , Cl(-1), whose, , -, , calculated as, can be, , (), , of metal, the two. The oxidation state, , and, this complex the ligands a r e NH,(0), of cobalt is, Therefore. Oxidation state, bracket., the, in, given, , (III) as., x+0x 4 -2-1 =, , 0, , *-3, , 0, , =3, , (ii), , chloride where, n a m e, , tetraamminedichlorocobalt (II), Thus, n a m e of complex is, a s one word n a m e ., of complex part is written, c o u n t e r ion is K(+1)., a r e CN-1) and, ligands, this, complex, the, brackett. Therefore,, K|Fe(CN),l : In, and counter ion a r e given in the, , The oxidation state of ligand, , iron is (II), the oxidation state of, 4 -1 x6, , as, , x+1x, x+4 6, * -2, , 0, , 2, is, potassium tetracyanoferrate (ID). Similarly,, Thus, the n a m e of complex, as, ion, , oxidation state and, , name, , of complex, , iii) For, [Au(CN),I-: The charge, 1, x-, , (iv), , on, , 1, , x, , 2, , =, , x, , -, , 2, , =, , -, , x, , =, , 2-1, , CN, , or, =, , given, , complex, , -1, Then, , the, , or., , State, , of Au, , is (I), , as, , -, , 1, , F o r |Cu(NH,),12*: The charge on NH, = 0, then oxidation s t a t e of C u is ( I ) a s, , +2, , x+0 x 4, x +0, , =, , +2, , 2, , | Pt(NH),(NO,)Cl|SO,:"The charge on NH, 0, NO,, Then, the oxidation state of Pt is (IV) as, So=-2., x+0x 4 - 1 - 1-2 =, 0, , (), (v For, , =, , x -, , 4, , =, , 0, , =, , -, , 1, Cl, , =, , -, , 1 and

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6, , LAXMI Text Book Series, II a complex posses zero oxidation states, mentionea, Dy the name of metal. For example, In complex, compou, The oxidation state on, CO 0, Then, =, , -, , x+0x 4, , we, , INi(CO), , =0, , =0, , The name of complexis tetracarbonylnickel (o)., , 8. Naming of the, bridging, (i) &complex has bridgingligands, ligand, the prefix u(mu), , is used, , before the name, , of eaa, , Ach, , ligands Fig. 28., , For example, (a) The name of complex I(NH,), Co, , NH,, , -, , Co(NH,),(H,O)JCI,, -, , (I), , 1-amidotetraammineaquacobalt, , chloride., , cobalt (I), ligands use, u-di, has two similar bridging, complex, 1s, a, For example: thé n a m e of complex, -, , (NH Co, , for its, , is, , taammine, , pentaammi, , name, , Co (NH)|(SO)2, N, , Ha, , Tetraamminecobalt(IIDu-diamidoteraamminecobalt (III) suuphate, (c), , When, , more, , than two, s a m e bridging, , ligands.present, u s e, , jH-tri before their nam, , CO, (NH) Fe -COFe (NH,)3, Co, , triammine iron, , (d), , di-iron (o), When the same, , (o) u--tricarbonyltriammineiron (o), , or, , p-tricarbonylhexaammine, , bridging ligands and as a non bridging, is named first, for example:, ligand (terminal, the bridging ligands, ligand is present, , as a, , CO, , (CO) Fe-c0Fe (CO)3, co, , -tricarbonylhexacarbonyldi-iron (o), Name of few bridging complex discussed as., , H, O, , (i), , Fe (H,0)|SO, , (H,0), Fe, H, , 1a-p", , tetraaquairon(II)-u-dihydroxotetraaquairon(II)sulphate or oue, , dihydroxodiiron (II) sulphate.