Nickel(II) complexes with N-aralkyliminodiacetic acids: Preparation, spectroscopic, structural and thermal characterization

Inert Transition Metal Ion Complexes in Organic Synthesis: Protection and Activation

“…Complex 14 can be regarded as an N-functionalised iminodiacetate and once again the fact that the substituent is cationic appears to have no great influence on the properties, here the Lewis basicity, of the substituent, NiÀ N and NiÀ O bond lengths being essentially identical with those of the Ni(II) complex of N-benzyliminodiacetate, for example. [50] (See also Table 1.) This is no doubt in part a reflection of the distance between cationic and anionic centres and it must be said that large effects are obvious in pK a measurements for N-centres directly attached to metallocages [2] compared to those for analogous free amines but to what extent solvation differences influence such data is obscure.…”

“…In contrast to the structure of 14 , the conformation of the Co(III) centres is ob 3 and each NH is bound to a separate acceptor, either chloride ion or water‐O. Complex 14 can be regarded as an N‐functionalised iminodiacetate and once again the fact that the substituent is cationic appears to have no great influence on the properties, here the Lewis basicity, of the substituent, Ni−N and Ni−O bond lengths being essentially identical with those of the Ni(II) complex of N‐benzyliminodiacetate, for example [50] . (See also Table 1.)…”

A diversity of hydrogen bond motifs in the crystal structures of nickel(II) and copper(II) complexes with N-arylalkyliminodiacetamides

“…Synthesis of the ligands N-Arylalkyl derivatives of iminodiacetamide, RN(CH 2 CONH 2 ) 2 , were prepared by the reaction of the corresponding amines with chloroacetamide in boiling acetonitrile, using potassium carbonate as a base (Scheme 2.). Chloroacetamide is much weaker alkylating agent than chloroacetic acid [23] and this was reflected on the considerably lower yields of iminodiacetamides Bnimda, Peimda and Ppimda when compared with the yields of the iminodiacetic acids H 2 Bnida, H 2 Peida and H 2 Ppida [16]. This preparation method was applied because it was not possible to prepare these ligands by the method used for the preparation of N-arylalkyliminodiacetic acids [16].…”

“…Chloroacetamide is much weaker alkylating agent than chloroacetic acid [23] and this was reflected on the considerably lower yields of iminodiacetamides Bnimda, Peimda and Ppimda when compared with the yields of the iminodiacetic acids H 2 Bnida, H 2 Peida and H 2 Ppida [16]. This preparation method was applied because it was not possible to prepare these ligands by the method used for the preparation of N-arylalkyliminodiacetic acids [16]. The attempt to prepare their amides by substituting chloroacetic acid with chloroacetamide in boiling alkaline aqueous solution resulted in cleavage of the amide groups and evolution of ammonia.…”

“…These ligands (Scheme 1) are amide derivatives of previously reported iminodiacetic acids [14][15][16].…”