Crystal structure of bis(2,6-diaminopyridinium) diaqua-bis- (2,6-pyridinedicarboxylato)-bis(2,6-pyridinedicarboxylato)- dibismuthate(III) tetrahydrate, (C28H16O18N4Bi2)(C5H8N3)· 4H2O (original) (raw)
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Polyhedron, 2015
Pd(II) chloride organometallics with 2-phenylpyridine and pyridines of general formula [Pd(2ppy ⁄ )LCl] (2ppy ⁄ = C(2 0 )-deprotonated form of 2-phenylpyridine (2ppy), acting as N(1),C(2 0 )-chelating ligand; L = NH 3 , pyridine, 2-, 3-, 4-methylpyridine, 2,3-, 2,4-, 2,6-, 3,5-dimethylpyridine, 2,4,6-trimethylpyridine) were studied by 1 H, 13 C and 15 N NMR. 1 H, 13 C and 15 N NMR coordination shifts (i.e. differences of chemical shifts for the same atom in the complex and ligand molecules) were discussed in relation to the molecular structures. Single crystal X-ray structure of trans(N,N)-[Pd(2ppy ⁄ )(2,4,6col)Cl] was solved. The analysis of 15 N NMR coordination shifts for the whole series of the studied organometallics exhibited that all of them had an analogous trans(N,N) geometry.
Kinetics and mechanism of the complex formation of [Pd(NNN)Cl]+ with pyridines in methanol: synthesis and crystal structure of Pd(terpy)(py)2
Inorganica Chimica Acta, 2004
The kinetics of the complex-formation reactions between monofunctional palladium(II) complexes [Pd(NNN)Cl] þ , where NNN is 2,2 0 :6 0 ,2 00 -terpyridine (terpy), diethylenetriamine (dien) or bis(2-pyridylmethyl)amine (bpma), with pyridine, 4-methylpyridine, 4acetylpyridine, 4-cyanopyridine and 4-aminopyridine, have been studied in methanol at 25°C using stopped-flow spectrophotometry. The highest reactivity was observed for the [Pd(terpy)Cl] þ complex, whereas 4-aminopyridine is the strongest nucleophile. The results, compared with those previously published on the [Pt(NNN)Cl] þ complexes, are discussed in terms of reactivity and discrimination ability of the reaction centre. The crystal structure of [Pd(terpy)(py)](ClO 4 ) 2 has been determined by X-ray diffraction. Crystals are triclinic, space group P 1, and consist of distorted square planar [Pd(terpy)(py)] 2þ cations and perchlorate anions. The Pd-N bond length to the central atom of terpy ligand is well below 2.0 A and significantly shorter than any of the other M-N distances. The pyridine plane forms a dihedral angle of 61.9(2)°with the coordination N4 donors.
Transition Metal Chemistry, 2014
Palladium(II) saccharinate (sac) and thiosaccharinate (tsac) complexes with 2-aminopyridine (2-ampy), 2-acetylaminopyridine (2-aampy) and 2-acetylaminopyrimidine (2-aampym) co-ligands: X-ray crystal structures of trans-[Pd(sac) 2 (ampy) 2 ] and solvatomorphs trans-[Pd(sac) 2 (2-aampy) 2 ]ÁS (S = CHCl 3 , thf) a b s t r a c t Reactions of Na 2 PdCl 4 with two equivalents of 2-aminopyridine (2-ampy), 2-acetylaminopyridine (2aampy) or 2-acetylaminopyrimidine (2-aampym) afford complexes of the type trans-[PdCl 2 L 2 ]. Further reaction with two equivalents of sodium saccharinate (Nasac) affords mixed-ligand complexes trans-[Pd(sac) 2 L 2 ]. X-ray structures of trans-[Pd(sac) 2 (2-ampy) 2 ] and two solvatomorphs of trans-[Pd(sac) 2 (2aampy) 2 ].S (S = CHCl 3 , thf) have been carried out. In all three, the saccharinate ligands coordinate in a monodentate fashion via the endocyclic amido group and all four ligands lie approximately perpendicular to the PdN 4 plane. In trans-[Pd(sac) 2 (2-ampy) 2 ] the metal ion lies on an inversion centre and consequently the ligands adopt a relative anti/anti-configuration, while in both solvatomorphs of trans-[Pd(sac) 2 (2-aampy) 2 ] they adopt a syn/syn-configuration, the latter possibly resulting from intramolecular hydrogen bonding between the amine protons and the carbonyl oxygen. Reactions of trans-[PdCl 2 L 2 ] with thiosaccharin (tsacH) are dependent upon the nature of the amine. Thus, with trans-[PdCl 2 (2ampy) 2 ] the desired mixed-ligand complex trans-[Pd(tsac) 2 (2-ampy) 2 ] results, however with acetylamine complexes only the known homoleptic complex, [Pd(tsac) 2 ], is isolated.
Organometallic Complexes of Palladium(II) Derived from 2,6-Diacetylpyridine Dimethylketal
Organometallics, 2010
PdCl 2 reacts with 2,6-diacetylpyridine (dap) (1:1) in refluxing MeOH to give the pincer complex [Pd(O 1 ,N 1 ,C 1 -L)Cl] (1) and (QH) 2 [{PdCl 2 ( μ-Cl)}] 2 (2), where L is the monoanionic ligand resulting from deprotonation of the acetyl methyl group of the monoketal of dap and QH is C 5 H 3 NH{C-(OMe) 2 Me} 2 -2,6, the diketal of Hdap þ . Reaction of 2 with NEt 3 (1:2) in MeOH affords Q = C 5 H 3 N{C(OMe) 2 Me} 2 -2,6 (3). Complex 1 reacts with 2 equiv of RNC at 0°C to give trans-[Pd(C 1 -L)Cl(CNR) 2 ] (R = Xy = 2,6-dimethylphenyl (4a), t Bu (4b)) but at room temperature affords [Pd(O 2 , C 2 -L R )Cl(CNR)] (R = Xy (5a), t Bu (5b)). The ligand L R results from the insertion of one isocyanide into the Pd-C bond plus a tautomerization process from β-ketoimine to β-ketoenamine and coordinates in 5 through the carbonyl oxygen atom (O 2 ) and the inserted isocyanide carbon atom (C 2 ). The reaction of 1 with 1 equiv of RNC at 0°C leads to a mixture of [Pd(N 1 ,C 1 -L)Cl(CNR)] (R = Xy (6a), t Bu (6b); 85-90%), 1, and 4, but at room temperature gives the pincer complex [Pd(O 1 ,N 1 ,C 2 -L R )Cl] (R = Xy (7a), t Bu (7b)), resulting from insertion/tautomerization processes similar to that leading to 5. Complex 7 reacts at 0°C (1) with 2 equiv of RNC to give trans-[Pd(C 2 -L R )Cl(CNXy) 2 ] (R = Xy (8a), t Bu (8b)) or (2) with 1 equiv of t BuNC to afford 5b. The reaction of 1 (1) with [Tl(acac)] gives [Pd(N 1 ,C 1 -L)(acac)] (9); (2) with chelating ligands N ∧ N affords [Pd(C 1 -L)Cl(N ∧ N)] (N ∧ N = 2,2 0bipyridine = bpy (10), 4,4 0 -di-tert-butyl-2,2 0 -bipyridine = dbbpy (11)); (3) with 1 equiv of PPh 3 gives, in the same way as with isocyanides, an equilibrium mixture of [Pd(N 1 ,C 1 -L)Cl(PPh 3 )] (12), 1, and trans-[Pd(C 1 -L)Cl(PPh 3 ) 2 ] (13), which is the only product when 2 equiv of PPh 3 is added to the reaction mixture; and with excess PPh 3 affords the monoketal of dap, C 5 H 3 N{C(O)Me-2}{C(OMe) 2 Me-6} (14), and [Pd(PPh 3 ) 4 ]. The crystal structures of complexes 1, 2, 5b, 6a, and 7a have been determined. *Corresponding authors. E-mail: jvs1@um.es (J.V.); aurelia@um.es (A.A.). Web: http://www.um.es/gqo/.