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Three Pd(II) complexes of some hemilabile ligands, aminothiazole-based phosphines, were synthesized to investigate the catalytic activity of them in Heck cross-coupling reactions. The crystal structures of complexes PdCl2[(Ph2P)HN(C3H2NS)] ( C 1) and PdCl2[(Ph2P)HN(C7H4NS)] ( C 3) were determined using X-ray crystallography, which reveals that the ligand coordinates in a chelating mode through P and N (endocyclic) atoms in square planar geometry. Experimental and theoretical studies (atoms in molecules and natural bond orbital analyses) show that the Pd(II) interacts more strongly with the P atom than the N atom in the chelated ligand, N^P. This trait can promote catalytic activity of the complexes in comparison with our previous work in which chelated ligands with two phosphorus atoms, P^P, were used. The influence of non-covalent intermolecular interactions on the assembly of the solid-state structures is also discussed in terms of geometrical analysis. The prepared complexes turn out to be useful pre-catalysts in Heck cross-coupling reactions owing to the coordinative flexibility of the hemilabile ligands. The protocol affords the corresponding products in greater yield than the same reactions with bis(phosphino)amine Pd(II) complexes, as the catalysts in our previous work. [ABSTRACT FROM AUTHOR]

2,4-Bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide ( Lawesson’s reagent ) was made to react with benzylamine to produce [(PhCH 2 NH)(p-C 6 H 4 OMe)PS 2 ] − [PhCH 2 NH 3 ] + in a very facile manner. From the abovementioned product, two new complexes {Pd[(PhCH 2 NH)(p-C 6 H 4 OMe)PS 2 ] 2 } (C1) and {Cu 2 (PPh 3 ) 2 [(PhCH 2 NH)(p-C 6 H 4 OMe)PS 2 ] 2 } (C2) were obtained in high yields whose molecular structures were ascertained by X-ray diffraction analysis, IR and NMR spectroscopy, and elemental analysis. The catalytic properties of both complexes were evaluated in the Heck reaction. High turnover numbers (TONs) and yields were observed for palladium catalyst and it was revealed that dicopper(I) complex by a distance of 2.84 Å between metal ions, bearing triphenylphosphine and dithiophosphorus ligands, can catalyze the Heck reaction. This is the first report of Cu(I) complex as catalyst in the Heck reaction. Natural bonding orbital (NBO) analysis for C1 indicated that natural charge on Pd atom is −0.07e and Pd atom has formed four sigma bonds with S atoms. Similarly, NBO analysis revealed no significant Cu⋯Cu interaction in dicopper complex C2. [ABSTRACT FROM AUTHOR]

Two new diorganotin complexes with formula {SnCl 2 (CH 3 ) 2 L1} 2 (C1), L1 = N-nicotinyl, N′,N″-bis(diethylamine) phosphoric triamide and {SnCl 2 (CH 3 ) 2 L2} n (C2), L2 = N-nicotinyl, N′,N″-bis(cyclopentylamine) phosphoric triamide were synthesized and characterized by IR and NMR spectroscopy, and elemental analysis. Single crystal X-ray diffraction structural analyses confirmed all-trans and cis–trans configurations for distorted octahedral geometry in C1 and C2, respectively. Also, it revealed that the coordination of L1 and L2 to Sn atom results to a binuclear arrangement in C1 and one-dimensional polymeric chain in C2. The relative stability of M1 (SnCl 2 (CH 3 ) 2 L1) and M2 (SnCl 2 (CH 3 ) 2 L2) units in binuclear and polymeric arrangements were compared using density functional theory (DFT) calculations. Based on theoretical findings, M1 and M2 prefer polymeric chain structure from energy point of view though the stability difference of M1, in two arrangements, was much lower compared to stability difference of M2. Furthermore, nature of bonds and Sn–ligand interactions was studied by NBO analyses. In vitro cytotoxic assay of complexes against breast cancer cell lines MCF-7, MDA-MB-468 and T47-Dhuman, were also reported. MDA-MB-468 cells are exquisitely sensitive to cell death induced by C1 and C2 complexes treatment. C1 complex exhibited higher anticancer activity, compared to C2, which can be attributed to larger Cl Sn Cl angle in C1. [ABSTRACT FROM AUTHOR]

Two N , N -bis(diphenylphosphino)-amine ligands [amine = 4-aminomorpholine ( L 1 ) or 1-amino-4-methylpiperazine ( L 2 )] and their Pd(II) complexes were synthesised and characterised by IR and NMR spectroscopies. The structures of ligand L 1 and both complexes C 1 and C 2 were determined by X-ray crystallography. The catalytic activity of C 1 and C 2 in the Heck coupling reactions was assessed. The effect of parameters such as palladium source, solvent, base and reaction time on the conversion was investigated to obtain the optimum conditions for the reaction. [ABSTRACT FROM AUTHOR]

Organotin complexes of bisphosphoramidates were prepared by the reaction of SnR 1 R 2 R 3 Cl (where R = alkyl/aryl/Cl) and Ph 2 P(O)XP(O)Ph 2 ligands (where X = diamine). All the compounds were characterized by NMR and IR spectroscopy. X-Ray crystallography confirms that the bridging ligand produces binuclear complexes with SnPh 3 Cl acceptors in C a3 and C a4 and offers a polymeric structure toward SnMe 2 Cl 2 in C c5 . The synthesized compounds were screened for the antibacterial activity against B. cereus and E. coli . Based on the MIC test, the ligands are devoid of antibacterial activity. Notably, among the complexes, triphenyltin adducts exhibited a marked activity only against Gram-positive bacterium B. Cereus (IC 50 = 0.78 μg/mL for C a3 and C a5 ). DFT–QSAR models revealed that the descriptor of the electrophilicity ( ω ) parameter is correlated with the inhibition activity on B. cereus . The correlation matrix of QSAR models and docking analysis confirmed that the electrophilicity parameter controls the influence of the net charge ( Q Sn ) and polarizability of Sn atom of complexes on the inhibition of B. cereus . [ABSTRACT FROM AUTHOR]

New Ag(I) complexes of N-nicotinyl, N′,N″-bis(cyclohexyl) phosphoric triamide, 3-NC 5 H 4 C(O)NHP(O)[NH(C 6 H 11 )] 2 ( L 1 ), and N-nicotinyl, N′,N″-bis(tert-butyl) phosphoric triamide, 3-NC 5 H 4 C(O)NHP(O)[NHC(CH 3 ) 3 ] 2 ( L 2 ), with formula Ag( L 1 ) 2 NO 3 ( C 1 ) and Ag( L 2 ) 2 NO 3 ( C 2 ) were synthesized and characterized by NMR, IR, UV–Vis spectroscopy and elemental analysis. Molecular structures of C 1 and C 2 were determined by X-ray crystallography and revealed that coordination of ligands to Ag(I) has been occurred from the nitrogen atom of the pyridine ring. Also, compound C 1 exists as two conformers in crystalline structure which are weakly connected to each other through intermolecular Ag…O C electrostatic interaction. Ag(I) complexes and the corresponding ligands were screened for their antibacterial activity against selected Gram-positive and Gram-negative bacteria, showing bactericidal activity for complexes. In vitro cytotoxicity of compounds was studied against human carcinoma cell lines, HeLa (cervical cancer), MCF-7 (breast cancer) and MG-63 (osteosarcoma). Results indicated that C 1 and C 2 possess strong cytotoxic activity against cancer cells with IC 50 values ranging from 3.3 to 15.3 μM for two exposure time (24 and 48 h). The cytotoxicity of complexes against non-tumorigenic breast cell, MCF-10A was further evaluated. Structure–activity relationships have been also discussed. [ABSTRACT FROM AUTHOR]

The reaction of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson reagent) with isobutanol, cyclohexylamine and phenylethylamine produced (4-methoxy-phenyl)-phosphonodithioic acid o-isobutyl ester HSP(p-CHOMe) (OCHCH(CH)) ( I), [SP(CHNH)(p-CHOMe) HNCH] ( II) and [SP(phCHCHNH) (p-CHOMe)HNCHCHph] ( III), respectively. The reaction of alcohol with Lawesson reagent produced neutral product ( I) while that with amines led to an ion pair ( II, III). Furthermore, reaction of I, II and III with NiCl.6HO in methanol produced novel complexes: IV, V and VI. The compounds were characterized by H, C and P NMR, IR spectroscopy and elemental analysis. The single crystal X-ray structures of IV and V showed that the nickel complexes are square planar. Compound V formed a three-dimensional supramolecular structure via intermolecular P-O ...H-N hydrogen bonds. The X-ray crystallography of V showed that those three hydrogens of NH cation produced three hydrogen bonds with different distances. The new compounds were additionally tested in view of their anti-bacterial properties. The ligands containing amine substituents exhibited more activity toward tested bacteria than their alcohol substituents, while the Ni(II) complexes including alcohol substituents exhibited high potential. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A new phosphoryl-containing ligand, N-isonicotinyl, N?,N??-bis(hexamethylenyl) phosphoric triamide (1), was synthesized and characterized using IR,1H,13C, and31P NMR and UV–vis spectroscopy. Reaction of1with MnCl2·4H2O led to the formation of Mn(II) complex with the formula {Mn[4-NC5H4C(O)NHP(O)(NC6H12)2]2Cl2}n(2). Crystal structures of1and2were determined by X-ray crystallography, which reveals that2is centrosymmetric with two phosphoryl oxygens, chloride and nitrogen intranspositions. Coordination of bridged bidentate1through oxygen of the phosphoryl and nitrogen of the pyridine afforded a 3-D network extended by coordinative bonds. Compound2and its nano-sized particles prepared by sonochemical method were characterized by IR spectroscopy, X-ray powder diffraction, and thermal analysis and exhibited paramagnetic behavior at room temperature. Crystalline mixture of Mn2P2O7and Mn2P4O12was identified as a thermolysis product of2. [ABSTRACT FROM PUBLISHER]

Ten new N-nicotinyl and N-isonicotinyl phosphoramidates with formula XP(O)R, X = Nicotinamide(nia), R = NHCHPh ( 1), N(CH)CHPh ( 2), NHCH(CH)Ph ( 3), NH-CHCHO ( 4), NHCH(CHN) ( 5), 3-NH-CHN ( 6), and YP(O)R, Y = isonicotinamide(iso), R = NHCHPh ( 7), N(CH)CHPh ( 8), NHCH(CH)Ph ( 9), NH-CHCHO ( 10) plus one new Er(III) complex with formula Er(L)(NO) ( 11), L = (iso)PO(NHCHCHO) ( 10), were synthesized and characterized by elemental analysis and H, C, P NMR, IR, UV-vis spectroscopy. Crystal structures of compounds 10 and 11 were also determined by X-ray crystallography. Interestingly, the H NMR spectra of compounds 1, 2, 6, 7, 9 indicated long-range J ( n = 5,6,7) coupling constants, in the range of 1.4-1.9 Hz, for the splitting of pyridine ring protons with phosphorus atom. IR results showed that the ν(C=O) values of compounds 7- 10 are greater than those of compounds 1- 5 which means that isonicotinyl moiety is more electron withdrawing than nicotinyl group. X-ray outcomes revealed that in complex 11 three phosphoric triamide ligands have been connected to each Er(III); one from N and two from P=O donor sites. One of the P=O donor ligands is mono dentate while the other one acts as a bidentate ligand and coordinates to another Er atom via its N site. By forming complex 11 the P=O and C-N bond lengths of ligand is increased in both, mono and bi dentate, ligands while the C=O bond length is decreased to lower values. These variations are in good agreement with IR results. All H-bonds and electrostatic interactions lead to form a three-dimensional polymeric cluster in the crystal lattice of 10 and 11. [ABSTRACT FROM AUTHOR]

The ligand (C6H5)2P(O)NC4H8O (L) was synthesized and used to prepare new octahedral complex mer-[(C6H5)2(NC4H8O)PO]3LaCl3 (LaL3Cl3). In the solid state structure of LaL3Cl3, the chloride anion trans to neutral ligand L3 (Cl2) has an inverse trans influence, while the La–O3 (trans to Cl2) distance is slightly shorter than the La–O1 and La–O2 distances (La–O1 trans to La–O2). On the contrary, the La–O3 distance is considerably longer than the La–O1 and La–O2 distances in the gas phase structure of LaL3Cl3, as a result of the normal trans influence of Cl2. The La–Cl2 (trans to La–O3) binding energy is larger in magnitude than the calculated values for the La–Cl1 and La–Cl3 bonds. The directional dependence of La–ligand bonding is in agreement with the trends in calculated electron density (ρ) values at bond critical points (bcp’s) and wiberg bond indices. Based on the results of atoms in molecules (AIM) analysis, the positive values for the electronic energy density, H(r), at the bcp of La–O bond paths suggest an ionic character for the La–O bonds, and the small negative values for H(r), at the bcp of La–Cl bonds, indicate a partial covalent character of the La–Cl interaction. The NBO analysis reveals a partial occupancy of La 5d and 6s orbitals which is originated from the ligand to metal charge transfer (LMCT) in complex LaL3Cl3, agreeing with the loss of electron density from the coordinated ligands L and chloride counterions. [ABSTRACT FROM AUTHOR]

Abstract: Three new carbacylamidophosphates with formula CH n Cl3−n C(O)NHP(O)(NHCH(CH3)2)2 (n = 2 (1); n = 1 (2); n = 0 (3)) and their organotin compounds with formula (1)SnCl2Me2(μ-1)SnCl2Me2 (4), SnCl2Me2(2)2·C6H5CH3 (5) and [SnCl2Me2(3)] n (6) were synthesized and characterized by elemental, IR and NMR spectra analyses. The spectroscopic properties of complexes were compared with those corresponding ligands. The crystal structures of complexes were determined by X-ray crystallography, which reveals that complex 4 is binuclear structure with two non-equivalent Sn atoms. One adopts a distorted trans(C,C) cis(OP,OP) cis(Cl,Cl) octahedral configuration, while the other adopts a distorted trigonal bipyramidal geometry composed of two methyl groups, two chlorine atoms and carbonyl group. Molecule 5 is centrosymmetric with two OP, disordered chlorine and methyl groups in trans positions. Toluene molecules are located in the interlayer spaces of 5. In compound 6, bonding via both PO and CO functionalities forms 1D infinite chain structures along b axis. The Sn–OP bond length in 6 is significantly longer than the same distance in 4 and 5, while the O#x2013;Cl bonds are shorter. The bond lengths in these complexes were compared with those of N-benzoyl carbacylamidophosphates. [Copyright &y& Elsevier]

Abstract: Four new phosphoramidates with formula 4-RC6H4C(O)NHP(O)(NH(CH(CH3)2)2, R=H (1), OCH3 (2), CH3 (3), Cl (4) and their diorganotin(IV) complexes with formula SnCl2(CH3)2(X)2, X= 1 (5), 2 (6), 3 (7) and 4 (8) were synthesized and characterized by NMR, IR spectroscopy and elemental analysis. The spectroscopic properties of complexes were compared with those corresponding ligands. The molecular structures for 5, 5·CH3CN, 6·CH3CN, 7 and 8 were established by X-ray diffraction analysis and shown that the tin atoms have a distorted octahedral coordination with trans-methyl groups. Two different all-trans and cis–trans isomers were obtained by changing the crystallization solvent system. The existence of CH3CN in molecular packing of trans–cis isomers might be a packing factor governing the orientation of the ligands. Due to the presence of several hydrogen bond donors and acceptors on compounds, extended hydrogen-bonded networks were observed. The structure of 2 was also determined and possesses two crystallographically independent molecules in asymmetric unit. On forming complex 6·CH3CN, the ligand 2 shows shortening of Cx2013;N bond distances and increasing of Pngth. Pseudopolymorphism of diorganotins in 5 and 5·CH3CN is reported for the first time. [Copyright &y& Elsevier]

Abstract: Monodentate and bidentate ligands PhNHP(O)(NC4H8O)2 (1) and PhC(O)NHP(O)(NH(tert-C4H9))2 (2) were used to prepare new 7, 9 and 10-coordinated lanthanum(III) complexes; La(1)2Cl3(H2O)2 (3), La(1)2(NO3)3H2O.La(1)2(NO3)3CH3CN (4) and La(2)2(NO3)3 (5), respectively. Crystallization of compound 2 in CH3OH:CH3CN leads to one conformer in contrast to the crystallization result from CHCl3:n-C7H16 (two conformers). Compound 4 contains two independent nine-coordinated La(III) complexes that are different in the solvated molecules (H2O and CH3CN). Some structural and electronic perturbations in coordinated ligand were occurred upon complexation, that are confirmed by increase of 2 J PH, 3 J PH and 6 J PH coupling constants from the free ligand 1 to complexes 3 and 4. The steric repulsions in the first coordination sphere of La3+ ion, metal–ligand (M–L) binding strength and Ping frequency are very influenced by changing the counter ion from Cl− to . Comparing the X-ray crystallography data of free ligand 2 with bis-chelated complex 5, it is found that the phosphoryl group is more reactive than carbonyl counterpart. A blue shift of the ν(N–H) vibration is observed in line with the weakening of the hydrogen bond from N–H···OPhosphoryl in 1 to N–H···Cl in 3. Three dimensional butterfly-shape structures are seen in the unit cell of complex 3, which are produced by OWater–H···OMorpholine hydrogen bonds. [Copyright &y& Elsevier]

Three novel phosphoramidate ligands with formula , RP(O)R2', R=Nicotinamide(nia), R′=NHC(CH3)3(L1 ), NH(C6H11) (L2 ); R=isonicotinamide(iso), NH(C6H11) (L3 ) and their new organotin(IV) complexes with formula SnCl2(CH3)2(X)2, X=L1 (C1 ), L2 (C2 ), L3 (C3 ) plus SnCl2(CH3)2(L4)2(C4 ), L4 =isoP(O)[NHC(CH3)3]2, were synthesized and characterized by 1H, 13C, 31P,119Sn NMR, IR, UV–Vis spectroscopy and elemental analysis. Two novel complexes of nia and iso with formula SnCl2(CH3)2(X)2, X=nia (C5 ), iso (C6 ) were also prepared and all the complexes were spectroscopically studied in comparison to their related ligands and to each other. The crystal structure of complexes C1 , C3 , C4 , and C5 were determined by X-ray crystallography. –Sn–Cl···H–N– major hydrogen bonds beside other electrostatic interactions produced a three dimensional polymeric cluster in the crystalline lattice of C1 , C3 , C5 and a two dimensional polymeric chain in C4 . Results showed that coordination of the phosphoramidate ligand (L4 ) to Sn in C4 has been occurred from the nitrogen site of the pyridine ring similar to C5 , C6 in which there is no Pite; however, in C1 and C3 the active donor site of corresponding ligands is P＝O. It seems that in these complexes there is a competition between P＝O and Npyridine donor sites and the influential factor which determines the winner site is the type of substituents on phosphorus atom. [Copyright &y& Elsevier]

Abstract: The complexation reaction between uranyl (II) nitrate, and N-methyliminobis(methylenephosphonic acid) (MIDPH) was investigated in two different binary solvent mixtures of D2O–DMSO-d 6 at various temperatures using 31P NMR spectroscopy. The exchange between the free ligand and the 1:1 complexed ligand was slow on the NMR timescale and two 31P NMR signals were observed. The formation constant of the resulting complex was evaluated from integration of the two 31P NMR signals. The values of thermodynamic parameters of the resulting complex (ΔH, ΔS and ΔG) were determined from the temperature dependence of the formation constants. In the two solvent mixtures studied, the resulting complex is enthalpy stabilized but entropy destabilized. [ABSTRACT FROM AUTHOR]