Synthesis, spectroscopic, and structural characterization of new functionalized gem-bisphosphonate complexes of tin(IV) chloride

The authors are grateful to the Tunisian Ministry of High Education and Scientific Research and Technology for financial support of this researchBisphosphonates of the types X(P(O)(OEt)2)2 (X = CH2=C (1a), CNCH2CH (1b) and PhCH2NCH2CH (1c)) react with SnCl4 in anhydrous dichloromethane to produce the new tin(IV) adducts [SnCl4(1a)] (2a), [SnCl4(1b)] (2b) and [SnCl4(1c)] (2c) in 72-80% yields. These complexes were characterized using IR, multinuclear (1H, 13C, 31P, 119Sn) NMR spectroscopy, elemental analysis, and in one case by single crystal X-ray diffraction. The NMR data show that the bisphosphonate ligands are coordinated to the tin center in a bidentate fashion forming cis octahedral tin complexes. Furthermore, the X-ray structure of complex 2b reveals that the bisphosphonate ligand is coordinated in a bidentate manner to the metal center in a distorted octahedral arrangement with Sn-O-P bond angles in the range 135.95(16)–137.99(18)°. The P=O and Sn-O bond lengths of 1.495(3)-1.497(3) and 2.134(3)-2.146(2) Å, respectively are in the order expected for phosphonate tin(IV) complexes. The results are discussed and compared with closely related analogues.PostprintPeer reviewe

Synthesis, characterization, and structural properties of mercury(II), cadmium(II) and zinc(II) tripiperidinophosphine chalcogenide complexes

We are grateful to the Tunisian Ministry of High Education and Scientific Research for support [grant number LR99ES14] and to the French Service for Cooperation and Cultural Action in Nouakchott, Mauritania for a scholarship to FE.Reaction of metal chlorides (MCl2) with tripiperidinophosphine chalcogenides (Pip3PE) produces new dimer species ( 1-6 ) of the formula [MCl2(Pip3PE)]2 (Pip = piperidinyl; E = S or Se; M = Hg, Cd or Zn). These coordination complexes were characterized by elemental analysis, IR, multinuclear (31P, 113Cd and 199Hg) NMR spectroscopy and single crystal X-ray analysis. Compounds 1-6 exist as centrosymmetric homobimetallic dimers, [M(µ-Cl)Cl(Pip3PE)]2. Each dimer incorporates two µ2-chloro atoms and two terminal M–Cl bonds. The E atom of Pip3PE forms terminal M–E bonds {S; 2.305(11); Se: 2.412(6)-2.589(15) Å} and thus the geometry about each metal centre is distorted tetrahedral and the range of tetrahedral bond angles is 102.83(3) to 113.32(3)o. The P=Se bond lengths of 2.183(9)-2.205(2) Å in the selenide complexes are slightly elongated compared to those in the free ligands [2.1090(4) Å]. The results are discussed and compared with those obtained for related analogues.PostprintPeer reviewe

Synthesis and Characterization of a New Series of Bis(allylic-α-aminophosphonates) under Mild Reaction Conditions

Several bis(α-aminophosphonates) have been conveniently prepared in good yields using a straightforward multicomponent Kabachnik–Fields reaction between ethane 1,2-diamine or propane 1,3-diamine, diethylphosphite and aldehydes under catalyst-free conditions. The nucleophilic substitution reaction of bis(α-aminophosphonates) prepared and ethyl (2-bromomethyl)acrylate under mild reaction conditions afforded an original synthetic approach to a new series of bis(allylic-α-aminophosphonates)

Synthesis, characterization, and structures of zinc(II) and cadmium(II) complexes with phosphoramides bearing cyclic amino groups

Twelve new zinc(II) and cadmium(II) complexes with symmetric ligands, [MCl2((R2N)3PO)2] (M = Zn, R2N = pyrrolidinyl (1), piperidinyl (2); M = Cd, R2N = pyrrolidinyl (3), piperidinyl (4)), and differently substituted ligands of the general formula [MCl2(R2N)PO(R’2N)2] (M = Zn or Cd; R2N = Pyrr, Pip or Mor; R’2N = Pyrr, Pip or Mor (5–12) have been synthesized from reaction of zinc(II) or cadmium(II) chlorides with the ligands, giving yields of 43–76%. The complexes were characterized with multinuclear (1H, 13C and 31P) NMR, conductivity, IR spectroscopy, and X-ray analyses. Complexes 1, 3, 11, and 12 are comprised of two ligands coordinated to the metal center in a distorted monomeric tetrahedral arrangement. The P = O bond lengths of 1.490(3) (1), 1.497(4) (3), 1.480(4) (11), and 1.479(5) Å (12) are in the order observed for analogous phosphoramide complexes. The results are compared with those reported for related chalcogen counterparts