Vinyl polymerization of norbornene by mono‐ and trinuclear nickel complexes with indanimine ligands

A series of new indanimine ligands [ArN?CC₂H₃(CH₃)C₆H₂(R)OH] (Ar = Ph, R = Me ( 1 ), R = H ( 2 ), and R = Cl ( 3 ); Ar = 2,6‐i‐Pr₂C₆H₃, R = Me ( 4 ), R = H ( 5 ), and R = Cl ( 6 )) were synthesized and characterized. Reaction of indanimines with Ni(OAc)₂·4H₂O results in the formation of the trinuclear hexa(indaniminato)tri (nickel(II)) complexes Ni₃[ArN = CC₂H₃(CH₃)C₆H₂(R)O]₆ (Ar = Ph, R = Me ( 7 ), R = H ( 8 ), and R = Cl ( 9 )) and the mononuclear bis(indaniminato)nickel (II) complexes Ni[ArN?CC₂H₃(CH₃)C₆H₂(R)O]₂ (Ar = 2,6‐i‐Pr₂C₆H₃, R = Me ( 10 ), R = H ( 11 ), and R = Cl ( 12 )). All nickel complexes were characterized by their IR, NMR spectra, and elemental analyses. In addition, X‐ray structure analyses were performed for complexes 7 , 10 , 11 , and 12 . After being activated with methylaluminoxane (MAO), these nickel(II) complexes can polymerize norbornene to produce addition‐type polynorbornene (PNB) with high molecular weight M_v (10⁶ g mol^?1), highly catalytic activities up to 2.18 × 10⁷ gPNB mol^?1 Ni h^?1. Catalytic activities and the molecular weight of PNB have been investigated for various reaction conditions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 489–500, 2008     

Tris(triphenylphosphan)nickel(0)-Komplexe mit Nitril-Liganden

Tris(triphenylphosphane)nickel(0) Complexes with Nitrile Ligands . Synthesis, properties and reaction behaviour of (Ph₃P)₃Ni(η¹-NCR) (R = PhCH₂, 2-MeC₆H₄, Me₃Si) complexes as well as the X-ray structure of (Ph₃P)₃Ni(η¹-NCSiMe₃) are described. With NC(CH₂)_nBr (n = 1, 2) instead of the analogous nitrile complexes (Ph₃P)₂NiBr₂ and CH₃CN or C₂H₅CN respectively are formed.     

Untersuchungen zur Alkylierung von Bis-Stilbendithiolato-Komplexen des Ni(II), Pd(II) und Pt(II)

Investigation on the Alkylation of Bis-Stilbendithiolato Complexes of Ni^II, Pd^II, and Pt^II Alkylation reactions of co-ordinated ligands of the type of ethylene-bisthiol R₂S₂C₂²-proceed different depending on the substituents R. The neutral complexes isolated by a alkylation of the nickel bis-chelates (R = phenyl) according to Schrauzer and Rabinowitz and formulated by these authors as mixed ligand chelates of dithiolate and diether, were identified by us as complexes of the monoethers of the ligand. These nickel (II) complexes of the mono-ethers can not be alkylated further by alkyliodides. Oxidative coupling of two ligands yields disulfides which have been identified by mass spectroscopy thus indicating the original position of attack of the alkylating reagent. The formation of bis-monether complexes is reflected by the different charges on the S atoms of the model complex [Ni(CH₃S₂C₂H₂)(S₂C₂H₂)]- obtained from EHT and CNDO calculations. Both possible stereo-isomers have been isolated of the bis-methylmonether complex of Pt(II). Trans-[M((CH₃)(S₂C₂Ph₂))₂] (M = Ni(II), Pd(II)) form CH₂Cl₂ adducts. By treating the Ni-bis complexes of the monoalkylthioethers with iodine polyiodides are prepared. Binuclear Pd(II) complexes of composition [Pd₂((R)(S₂C₂Ph₂))₂Cl₂] could be prepared by metal exchange.     

Aluminiumorganic compounds of coordinated salicylaldoxime and their adducts with nitrogen Lewis bases

Aluminiumorganic compounds of a coordinated salicylaldoxime resulted from reaction of M(II)(SALOxH)₂ (where M(II) = Ni(II), Pd(II) and Cu(II); SALOx represents the divalent radical of the salicylaldoxime) with AlR₃(R = CH₃,C₂H₅,i‐C₄H₉,C₆H₅ and Cl). Copper(II) bis‐salicylaldoximate reacting with Al(i‐C₄H₉)₃ does not form a compound similar to those obtained with nickel and palladium. Aluminiumorganic compounds of the coordinated salicylaldoxime result from the substitution of O? H?O hydrogen bonds, existing in chelates, by O? Al? O bridges. All compounds reported in this paper were separated from the reaction mixture as coloured powders and were characterized by chemical analyses, IR spectroscopy, X‐ray diffraction spectra, proton NMR spectra and magnetic properties. The new aluminiumorganic compounds form adducts with amine. Among the amine adducts, only the adducts with pyridine were isolated to confirm their formula and the mode of binding. Copyright © 2001 John Wiley & Sons, Ltd.     

1,2-Bis-triphenylphosphoranylidenamino-äthan als zweizähniger Ligand in Übergangsmetallkomplexen

1,2-Bis-(triphenylphosphorane-ylidene-amino)ethane as a Bidentate Ligand in Transition Metal Complexes The reactions of Ph₃P?N? C₂H₄? N?PPh₃ with transition metal halogenides MX₂ give according to eq. (1) novel bisiminophosphorane complexes of the type M(Ph₃PNC₂H₄ NPPh₃)X₂ (M ? Co, X ? Cl 1 a , Br 1 b , J 1 c ; M ? Ni, X ? Cl 2 a , Br 2 b , J 2 c , M ? Hg, X ? Cl 3 , M ? Cd, X ? Cl 4 ). The preparation, properties, magnetic moments, and structure of the new complexes are reported     

Oxidative addition of different electrophiles with rhodium(I) carbonyl complexes of unsymmetrical phosphine–phosphine monoselenide ligands

Dimeric chlorobridge complex [Rh(CO)₂Cl]₂ reacts with two equivalents of a series of unsymmetrical phosphine–phosphine monoselenide ligands, Ph₂P(CH₂)_nP(Se)Ph₂ {n = 1( a ), 2( b ), 3( c ), 4( d )}to form chelate complex [Rh(CO)Cl(P∩Se)] ( 1a ) {P∩Se = η²‐(P,Se) coordinated} and non‐chelate complexes [Rh(CO)₂Cl(P～Se)] ( 1b–d ) {P～Se = η¹‐(P) coordinated}. The complexes 1 undergo oxidative addition reactions with different electrophiles such as CH₃I, C₂H₅I, C₆H₅CH₂Cl and I₂ to produce Rh(III) complexes of the type [Rh(COR)ClX(P∩Se)] {where R = ? C₂H₅ ( 2a ), X = I; R = ? CH₂C₆H₅ ( 3a ), X = Cl}, [Rh(CO)ClI₂(P∩Se)] ( 4a ), [Rh(CO)(COCH₃)ClI(P～Se)] ( 5b–d ), [Rh(CO)(COH₅)ClI‐(P～Se)] ( 6b–d ), [Rh(CO)(COCH₂C₆H₅)Cl₂(P～Se)] ( 7b–d ) and [Rh(CO)ClI₂(P～Se)] ( 8b–d ). The kinetic study of the oxidative addition (OA) reactions of the complexes 1 with CH₃I and C₂H₅I reveals a single stage kinetics. The rate of OA of the complexes varies with the length of the ligand backbone and follows the order 1a > 1b > 1c > 1d . The CH₃I reacts with the different complexes at a rate 10–100 times faster than the C₂H₅I. The catalytic activity of complexes 1b–d for carbonylation of methanol is evaluated and a higher turnover number (TON) is obtained compared with that of the well‐known commercial species [Rh(CO)₂I₂]^?. Copyright © 2006 John Wiley & Sons, Ltd.     

Nature of the complexes formed by alkali metal halides with phosphine oxides

Reaction of alkali metal halides (MX) with methylenediphosphine oxides and various related compounds in nonaqueous solutions leads to the formation of complex compounds. The compositions, properties, and stabilities of these compounds, which have been studied in detail in acetonitrile, are determined by the nature of the cations and anions of the alkali metal halides. Formation of neutral complexes with the composition [MX · L] and cationic complexes with the composition [ML]⁺ has been established. The most characteristic representative of complexes of the first type is [NaI · L]; in the complexes studied, L=R₂P(O)CH₂P(O)R₂ (R=Bu, BuO, or Ph), Ph₂P(O)CH₂P(O) (OC₂H₅)CH₂P(O)Ph₂ and (p-OCH₃C₆H₄)₂P(O)CH₂P(O)(C₆H₄CF₃-p)₂. Compound [LiL]⁺ is characteristic of complexes of the second type; the compounds containing Ph₃P(O), Ph₂P(O)CH₂P(O)Ph₂, and Ph₂P(O)CH₂P(O)(OC₂H₅)CH₂P(O)Ph₂ as ligands have been studied. Stability constants of the complexes [NaI · L] and [LiL]⁺ have been determined by measuring the dependence of the electrical conductivity of solutions of the alkali metal halides in acetonitrile on the concentration of the ligands. The complex-forming power of phosphine oxides increases with increase in the number of P=O groups. Stabilities of the complexes [NaI · L] with ligands with identical structure decrease with increase in the electronegativity of the substituents on the phosphorus atoms.     

Arene C?H Amination at Nickel in Terphenyl–Diphosphine Complexes with Labile Metal–Arene Interactions

The meta‐terphenyl diphosphine, m‐P₂, 1 , was utilized to support Ni centers in the oxidation states 0, I, and II. A series of complexes bearing different substituents or ligands at Ni was prepared to investigate the dependence of metal–arene interactions on oxidation state and substitution at the metal center. Complex (m‐P₂)Ni ( 2 ) shows strong Ni⁰–arene interactions involving the central arene ring of the terphenyl ligand both in solution and the solid state. These interactions are significantly less pronounced in Ni⁰ complexes bearing L‐type ligands ( 2‐L : L=CH₃CN, CO, Ph₂CN₂), Ni^IX complexes ( 3‐X : X=Cl, BF₄, N₃, N₃B(C₆F₅)₃), and [(m‐P₂)Ni^IICl₂] ( 4 ). Complex 2 reacts with substrates, such as diphenyldiazoalkane, sulfur ylides (Ph₂S?CH₂), organoazides (RN₃: R=para‐C₆H₄OMe, para‐C₆H₄CF₃, 1‐adamantyl), and N₂O with the locus of observed reactivity dependent on the nature of the substrate. These reactions led to isolation of an η¹‐diphenyldiazoalkane adduct ( 2‐Ph₂CN₂ ), methylidene insertion into a Ni? P bond followed by rearrangement of a nickel‐bound phosphorus ylide ( 5 ) to a benzylphosphine ( 6) , Staudinger oxidation of the phosphine arms, and metal‐mediated nitrene insertion into an arene C? H bond of 1 , all derived from the same compound ( 2 ). Hydrogen‐atom abstraction from a Ni^I–amide ( 9 ) and the resulting nitrene transfer supports the viability of Ni–imide intermediates in the reaction of 1 with 1‐azido‐arenes.     

Conjugate additions of functionalized carbanions to the vinylidene groups of [M(CO)4{(Ph2P)2CCH2}] (M = W,Mo or Cr)

Treatment of complexes of the type [M(CO)₄{(Ph₂P)₂CCH₂}] (M = W, Mo or Cr) with functionalized lithium reagents, LiR, followed by hydrolysis gives complexes of the type [M(CO)₄{PH₂P)₂CHCH₂R}] in high yields; R = C₆H₄Me-4, C₆H₄OMe-2, C₆H₃(OMe)₂-2,6, C₆H₄OH-2, C₆H₄(COOH)-2, CH₂COPh or CH₂COMe. IR, and ³¹P and ¹H NMR data are given.     

Oxydation von Nickel(0)-Komplexen mit cyclischen Carbonsäureamiden

Oxidation of Nickel(0) Complexes by Cyclic Imides of Dicarbonic Acids Normally, phthalimide (PI? H) or succinimide (SI? H) react with nickel(0) complexes — (dipy)Ni(COD) or (Ph₃P)₂Ni(C₂H₄) — by oxidative addition. The reaction of PI? H and the strong reductant (dipy)Ni(COD) is initiated by a one-electron transfer. Depending on the solvent, the resulting ion pair affords (dipy)Ni^I(PI) by spontaneous fragmentation or (dipy)Ni^II(H)(PI) by cage collaps. No interaction is found between the weak reductant (Ph₃P)Ni(C₂H₄) and PI? H. Phosphine-containing nickel(0) complexes are electrophilically attacked by the acid NH group of SI? H. Hydrido complexes of nickel(0), such as (Cy₃P)₂Ni(H)(SI), or secondary products of them, such as [(SI)Ni(THF)]₂NH, are formed. On the other hand, the reaction with (dipy)Ni(COD) affords only the binuclear substitution product [(dipy)Ni]₂(SI? H)(THF). In solution prolongated heating of (dipy)Ni(PI)(THF)_0,5 results in a partial decarbonylation. In contrast to the reaction of (dipy)Ni(COD) and cyclic carbonic acid anhydrides, no definite metalla rings but by an interaction with the solvent, benzamide is formed. With (dipy)Ni(COD) maleinimide does not react like on NH-acidic compound but like a polar olefine by substitution.     

Synthesis and characterization of new (N‐diphenylphosphino)‐isopropylanilines and their complexes: crystal structure of (Ph2P S)NH?C6H4?4?CH(CH3)2 and catalytic activity of palladium(II) complexes in the Heck and Suzuki cross‐coupling reactions

Three new (N‐diphenylphosphino)‐isopropylanilines, having isopropyl substituent at the carbon 2‐ (1) 4‐ (2) or 2,6‐ (3) were prepared from the aminolysis of chlorodiphenylphosphine with 2‐isopropylaniline, 4‐isopropylaniline or 2,6‐diisopropylaniline, respectively, under anaerobic conditions. Oxidation of 1,2 and 3 with aqueous hydrogen peroxide, elemental sulfur or gray selenium gave the corresponding oxides, sulfides and selenides (Ph₂P?E)NH? C₆H₄? 2‐CH(CH₃)₂, (Ph₂P?E)NH? C₆H₄? 4‐CH(CH₃)₂ and (Ph₂P?E)NH? C₆H₄? 2,6‐{CH(CH₃)₂}₂, where E = O, S, or Se, respectively. The reaction of [M(cod)Cl₂] (M = Pd, Pt; cod = 1,5‐cyclooctadiene) with two equivalents of 1,2 or 3 yields the corresponding monodendate complexes [M((Ph₂P)NH? C₆H₄? 2‐CH(CH₃)₂)₂Cl₂], M = Pd 1d, M = Pt 1e, [M((Ph₂P)NH? C₆H₄? 4‐CH(CH₃)₂)₂Cl₂], M = Pd 2d, M = Pt 2e and [M((Ph₂P)NH? C₆H₄? 2,6‐(CH(CH₃)₂)₂)₂Cl₂], M = Pd 3d, M = Pt 3e, respectively. All the compounds were isolated as analytically pure substances and characterized by NMR, IR spectroscopy and elemental analysis. Furthermore, representative solid‐state structure of [(Ph₂P?S)NH? C₆H₄? 4‐CH(CH₃)₂] (2b) was determined using single crystal X‐ray diffraction technique. The complexes 1d–3d were tested and found to be highly active catalysts in the Suzuki coupling and Heck reaction, affording biphenyls and stilbenes, respectively. Copyright © 2009 John Wiley & Sons, Ltd.     

Chemie polyfunktioneller Moleküle. 82. Neue Rhodium(I)-Chelatkomplexe mit N,N-Bis(diphenylphosphino)alkyl- und -arylaminen

Chemistry of Polyfunctional Molecules. 82. New Rhodium(1) Chelate Complexes with N,N-Bis(diphenylphosphino) alkyl- and -arylamines . [Rh(μ-Cl)(CO)₂]₂ ( 1 ) reacts with (Ph₂P)₂NR (2, a: R = C₆H₅, b: R = p-C₆H₄CH₃) in a molar ratio of 1:2 to give the square plane, ionic complexes [Rh{(PH₂P)₂NR}₂] [cis-Rh(CO)₂Cl₂] ( 3a, b ). By the reactions of [Rh(μ-Cl)(C₈H₁₂)]₂(C₈H₁₂ = 1.5-Cyclooctadiene) (4) with (Ph₂P)₂NR ( 2a–d ) (c: R = CH₃, d: R = C₂H₅) in the molar ratios of 1:4 the square plane 1:1 electrolytes [Rh{(Ph₂P)₂NR}₂]Cl ( 5a–d ) are obtained. Upon treatment of 5a–d in dichloromethane with CO the complexes [Rh(CO){(Ph₂P)₂NR}₂]Cl ( 6a–d ) are formed. They are only stable in solution and in CO atmosphere and were identified by infrared spectroscopy. The new complexes have been characterized, as far as possible, by conductometry, IR; FIR, Raman, ³¹P-NMR, and ¹H-NMR spectra.     

The Polarographic Studies of Substituent Effects in Pyridine Complexes of Transition Metals

Polarographic reduction half-wave potentials for the series of inorganic complexes M(RC₅H₄N)₂Cl₂ (M=Co(II), Ni(II), Cu(II), Zn(II), Cd(II); R=H, CH₃, NH₂, OH, CONH₃, CHO, COCH₂ COPh, Cl, Br and CH₂OH) are reported to show the substituent effects in these complexes. Consequently, the E_1/2 values correlated linearly with Hammett substituent parameters, the slope of the E_σ Vs σ plots evidently decreases in order of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II).     

Zur Oxydation von Nickel(0)-Komplexen mit Halogenverbindungen des Kobalt(II), Kupfer(II) und Zink(II)

Oxidation of Nickel(0) Complexes by Halogen Compounds of Cobalt(II), Copper(II), and Zine(II) In aceton as a solvent Ni(PPh₃)₄ is oxidized by; cobalt(II) complexes of the type (Ph₃P)₂CoX₂ to nickel(I) compounds. In the case of X = Cl (Ph₃P)₃NiCl and (Ph₃P)₃CoCl separately crystallize, while for X = Br the lattice compound CoNi(PPh₃)₆Br₂ and for X = I CoNi(PPh₃)₅I₂ are formed. CuBr₂ and Ni(PPh₃)₄ react to (Ph₃P)₂NiBr and (Ph₃P)_nCuBr. With (Ph₃P)₂ZnCl₂ also (Ph₃P)₃NiCl is formed But in this case the oxidant is hydrogen chloride originating from hydrolysis. The magnetic moments of the new compounds were measured and their vis and fir spectra compared with those of the simple compounds (Ph₃P)_nNiX (n = 2, 3) and (Ph₃P)₃CoX. The M–X stretching frequencies are assigned. The cobalt (I) complexes (Ph₃P)₃CoCl have identical (distorted tetrahedral) structures, but most probably the nickel (I) complexes have not.     

Synthesis and characterization of mixed-ligand complexes of nickel(II) with 5,5′-thiodisalicylic acid and amines

The 5,5′-thiodisalicylato complexes of nickel(II) with water, ammonia, methylamine and pyridine were synthesized and their structure established to be [Ni(TDSA)L₂·nH₂O], where TDSA = 5,5′-thiodisalicylic acid, [C₆H₃(OH)(COOH)SC₆H₃(OH)(COOH)]. LH₂O, NH₃ CH₃NH₂ or pyridine, and n=3 for H₂O, 2 for NH₃ and CH₃NH₃, and 1 for pyridine complexes, from elemental analysis, IR and electronic spectroscopy, and magnetic susceptibility measurement. The thermal behaviour of the complexes has been studied by TG and DTA. TG shows three main steps of decomposition, viz. dehydration, axial base liberation, and decarboxylation leading to the formation of NiO at the final stage.     

Transition metal complexes with bidentate ligands spanning trans-positions. Part XIV. Some complexes of 2,11-bis(diphenylphosphinomethyl)benzo[c]phenanthrene with platinum (0) and their reactivities

The ligand 2,11-bis(diphenylphosphinomethyl)benzo[c]phenanthrene ( 1 ) has been used to prepare complexes of the type [PtL( 1 )] (L ? C₂H₄, CH₂?CH? CO₂Me, PhC?CPh, MeC?CMe, MeO₂CC?CCO₂Me, (i-Pr)O₂CC?CCO₂(i-Pr), Ph₃P and CO). It is shown that these complexes are less labile than the corresponding species [PtL(Ph₃P)₂]. The preparation of complexes trans-[PtX(R)(1)] by oxidative addition of RX (RX ? PhCH₂Br and Mel) to [Pt(C₂H₄)(1)] is described. The isolation of [PtO₂(CH₃)₂CO(1)] is also reported.     

Physicochemical properties and complexing ability of <Emphasis Type="Italic">N</Emphasis>-(2-ethylhexanoyl)-<Emphasis Type="Italic">N</Emphasis>′-sulfonylhydrazines

The effect of substituent at the sulfonyl group on the physicochemical properties and complexing ability of the sulfonyl derivatives of 2-ethylhexanoic acid hydrazide of the general formula C₄H₉CH(C₂H₅)C(O)·NHNHSO₂C₆H₅R [R = H, CH₃, NO₂, NHC(O)CH₃, Cl] with respect to Cu(II), Co(II), and Ni(II) ions was studied.     

Reactions of methyl and ethyl halides with the complexes Ni[P(C2H5)3]4 and Ni(X)[P(C2H5)3]3

The rates of the thermal reaction of the nickel(0) complex Ni[P(C₂H₅)₃]₄ with the alkyl halides CH₃Br, CH₃I in toluene have been compared with those of the reactions of the nickel(I) complexes Ni(X)[P(C₂H₅)₃]₃ (X  Br,I). The organic products from CH₃X are methane and ethane, and those from C₂H₅I are ethane and ethylene. The reactivity of the nickel(I) complexes is 10–20 times less than that of the nickel(0) complex. The result suggest that the first step of the reaction of nickel(0) with CH₃I is the expected oxidative addition of the halide to the metal substrate. The intermediate thus formed decomposes to produce ethane (and small amounts of methane) without further reaction with the organic halide. This mechanism is supported by deuterium-labeling experiments.     

Conformational Effects of [Ni2(μ‐ArS)2] Cores on Their Electrocatalytic Activity

Two nickel complexes supported by tridentate NS₂ ligands, [Ni₂(κ‐N,S,S,S′‐N^Ph{CH₂(MeC₆H₂R′)S}₂)₂] ( 1 ; R′=3,5‐(CF₃)₂C₆H₃) and [Ni₂(κ‐N,S,S,S′‐N^iBu{CH₂C₆H₄S}₂)₂] ( 2 ), were prepared as bioinspired models of the active site of [NiFe] hydrogenases. The solid‐state structure of 1 reveals that the [Ni₂(μ‐ArS)₂] core is bent, with the planes of the nickel centers at a hinge angle of 81.3(5)°, whereas 2 shows a coplanar arrangement between both nickel(II) ions in the dimeric structure. Complex 1 electrocatalyzes proton reduction from CF₃COOH at ?1.93 (overpotential of 1.04 V, with i_cat/i_p≈21.8) and ?1.47 V (overpotential of 580 mV, with i_cat/i_p≈5.9) versus the ferrocene/ferrocenium redox couple. The electrochemical behavior of 1 relative to that of 2 may be related to the bent [Ni₂(μ‐ArS)₂] core, which allows proximity of the two Ni???Ni centers at 2.730(8) Å; thus possibly favoring H⁺ reduction. In contrast, the planar [Ni₂(μ‐ArS)₂] core of 2 results in a Ni???Ni distance of 3.364(4) Å and is unstable in the presence of acid.     

Spectroscopic,crystal structure and thermal studies of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) with 5-amino-4-arylazo-3-methyl-1-phenylpyrazole (aryl=C6H5,o-C6H4COOH,o-C6H4OH)

5-Amino-4-arylazo-3-methyl-1-phenylpyrazole (aryl?=?C₆H₅,o-C₆H₄COOH,o-C₆H₄OH) and its complexes with Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) ions were synthesized. The complexes are in the ratio 1?:?1 and 1?:?2 (metal?:?ligand). Ligands and complexes were subjected to elemental analysis, IR, Raman, UV-Vis and ¹H-NMR spectroscopy. The mass spectra of the ligands were discussed. Thermal analysis and magnetic measurements were carried out for the prepared complexes. The X-ray single crystal structure of [Ni(L1)₂] was performed. The investigated pyrazole compounds coordinate as bidentate ligands through amino and azo nitrogens or tridentate through NNO. The molar conductance of the chelates is measured and reflected the non-electrolytic nature of the prepared complexes.