Synthesis of Mercury(II) and Palladium(II) Organometallic Derivatives of Terephthaldehyde by Metalation, Transmetalation, Oxidation, and Condensation Reactions. X-ray Crystal Structures of trans-[PdCl{C6H3(CO2H)2-2,5}(PPh3)2]·Me2CO·2MeOH, trans-[PdCl{C6H3(CHO)-2-(CO2H)-5}(PPh3)2]·2CH2Cl2, and [Pd{C6H3(CHNC6H4NH2-4)-2-(CHO)-5}(N,N,N‘,N‘-Tetramethylethylenediamine)]CF3SO3. Molecular Assemblies through [Pd]−Cl···HO2C−Aryl and [Pd]−Cl···HOMe HO(O)C−Aryl Hydrogen Bonds

The organomercurials [HgCl{C 6 H 3 (CHO) 2 -2,5}] ( 1 ) and [Hg{C 6 H 3 (CHO) 2 -2,5} 2 ] ( 2 ) have been prepared by mercuriation of terephthaldehyde. Palladium complexes [PdCl{C 6 H 3 (CHO) 2 -2,5}(N-N)] (N-N = N, N, N ‘, N ‘-tetramethylethylenediamine (tmeda) ( 3 ) or 2,2‘-bipyridine (bpy) ( 3 ‘)) or trans -[PdCl{C 6 H 3 (CHO) 2 -2,5}(PPh 3 ) 2 ]·H 2 O ( 4 ) have been obtained by reacting (Me 4 N) 2 [Pd 2 Cl 6 ] or trans -[PdCl 2 (PPh 3 ) 2 ], respectively, with 1 or 2 . The reaction of potassium permanganate with complexes 3 and 3 ‘ or mercurial 1 results in the selective oxidation of the 5-formyl substituent affording [PdCl{C 6 H 3 (CHO)-2-(CO 2 H)-5}(N-N)] (N-N = tmeda ( 5 ), bpy ( 5 ‘)) or, respectively, a mixture whose major component is the fully oxidized [HgCl{C 6 H 3 (CO 2 H) 2 -2,5}] ( 7 ) or a mixture of isomers [HgCl{C 6 H 3 (CHO)-2-(CO 2 H)-5}]/[HgCl{C 6 H 3 (CO 2 H)-2-(CHO)}] ( 8a / 8b ) depending on the molar ratio of the reagents. The reaction of mixtures containing 7 or 8 with trans -[PdCl 2 (PPh 3 ) 2 ] give pure trans -[PdCl{C 6 H 3 (CO 2 H) 2 -2,5}(PPh 3 ) 2 ] ( 9 ) or trans -[PdCl{C 6 H 3 (CHO)-2-(CO 2 H)-5}(PPh 3 ) 2 ] ( 10 ), respectively. Complexes 3 and 3 ‘ react with amines and NaClO 4 ·H 2 O or Tl(CF 3 SO 3 ) to give, depending of the reaction conditions, cyclopalladated The mercurial 1 reacts with hydroxylamine to give the mercuriated oxime [HgCl{C 6 H 3 (CH NOH) 2 -2,5}] ( 14 ), which reacts with (Me 4 N) 2 [Pd 2 Cl 6 ] to give the cyclopalladated From 15 some derivatives have been prepared. Complex 3 reacts with NH 2 OMe to give The imine C 6 H 4 (CH NTo) 2 -1,4 (To = C 6 H 4 Me-4) reacts with palladium(II) acetate to give the dipalladated Hydrolysis of 20 in the presence of potassium bromide and bpy results in the formation of [C 6 H 2 {PdBr(bpy)} 2 -1,4-(CHO) 2 -2,5] ( 21 ), from which [C 6 H 2 {Pd(PPh 3 )(bpy)} 2 -1,4-(CHO) 2 -2,5](CF 3 SO 3 ) 2 ( 22 ) can be prepared. The structures of 9 ·Me 2 CO·1.5MeOH, 10 ·2CH 2 Cl 2 (R = C 6 H 4 NH 2 -4) ( 12c ‘) have been determined by X-ray crystallography.