Search

[Ag(OTf)L] complexes (L = RR′Se) were prepared, structurally characterized and tested for their in vitro antiproliferative activity.

The new diorganodiselenides [2,6-{E(CH2CH2)2NCH2}2C6H3]2Se2 (E = MeN, O) with N,C,N pincer groups were oxidized with SO2Cl2 to the corresponding organoselenium(II) chlorides of type [2,6-{E(CH2CH2)2NCH2}2C6H3]SeCl. The new chlorides, as well as the related [2,6-(Me2NCH2)2C6H3]SeCl, transfer easily the chlorine atom to [AuCl(tht)] (tht = tetrahydrothiophene), thus forming ionic species based on the organoselenium cations [2,6-{E(CH2CH2)2NCH2}2C6H3Se]+ or [2,6-(Me2NCH2)2C6H3Se]+ and the [AuCl2]− anion. The reaction between [2,6-(Me2NCH2)2C6H3]2Se2 and [(C6F5)Au(tht)] resulted in an ionic species as well, i.e. [2,6-(Me2NCH2)2C6H3Se]+[Au(C6F5)2]−. The room temperature 1H NMR spectra suggest a fast dynamic behavior in solution for all species, except the ionic [2,6-{O(CH2CH2)2NCH2}2C6H3Se]+Cl− and [2,6-(Me2NCH2)2C6H3Se]+[Au(C6F5)2]−, for which the 1H NMR resonances in the aliphatic region suggest that both N→Se intramolecular interactions are preserved in solution. The solid state structures of {[2,6-{O(CH2CH2)2NCH2}2C6H3Se]+Cl−}·H2O, [2,6-(Me2NCH2)2C6H3Se]+[AuCl2]− and [2,6-(Me2NCH2)2C6H3Se]+[Au(C6F5)2]− were established by single-crystal X-ray diffraction.

Several homo- and heteroleptic diorganotin(IV) dithiocarbamato halides of type RR'Sn(S2CNR″2)Cl [R = R' = Me, R'' = Me (1), Et (2); R = R' = nBu, R'' = Me (3), Et (4); R = 2-(Me2NCH2)C6H4, R' = Me, R'' = Me (5), Et (6)] and pseudo-halides of type RR'Sn(S2CNR″2)(NCS) [R = R' = Me, R'' = Me (7), Et (8); R = R' = nBu, R'' = Me (9), Et (10); R = 2-(Me2NCH2)C6H4, R' = Me, R'' = Me (11), Et (12); R' = nBu, R'' = Et (13), R' = 2-(Me2NCH2)C6H4, R'' = Me (14), Et (15)] were prepared by salt metathesis reactions, starting from either RR'SnCl2 or RR'Sn(NCS)2. In all compounds the dithiocarbamato ligand acts as a bidentate moiety. For the compounds 11–15, as well as for the species 5 and 6, of type RR'Sn(S2CNR″2)Cl, bearing aromatic groups with pendant arms attached to tin, the NMR spectra gave no clear evidence for a N→Sn coordination in solution at room temperature. The molecular structures determined by single-crystal X-ray diffraction for compounds 12 and 14, with one or two 2-(Me2NCH2)C6H4 groups, respectively, revealed the existence of intramolecular N→Sn interactions in solid state. The IR spectra suggest an isothiocyanato behavior of the NCS group in solid state in all cases, while the 119Sn NMR spectra gave no clear evidence for such a behavior in solution, as no 14N-119Sn couplings were observed. The single-crystal X-ray diffraction studies revealed molecular species for 7, 8 and 12, while 14 is a ionic compound with [{2-(Me2NCH2)C6H4}2Sn(S2CNMe2)]+ cations and SCN− anions.

Heteroleptic triorganotelluronium chlorides of the type [RPh2Te]+Cl− (1) and [R2PhTe]+Cl− (4) [R = 2-(Me2NCH2)C6H4] were obtained by reacting Ph2TeCl2 with RLi in 1 : 1 and 1 : 2 molar ratios. The reaction of TeCl4 with RLi (a 1 : 3 molar ratio) afforded a mixture of [R3Te]+Cl− (7) and [R2Te(OH)]+Cl− (10) after separation by column chromatography. Halogen exchange reactions using KX resulted in the corresponding [RPh2Te]+X− [X = Br (2), I (3)], [R2PhTe]+X− [X = Br (5), I (6)] and [R3Te]+X− [X = Br (8), I (9)]. The compounds were characterized by multinuclear NMR spectroscopy and mass spectrometry. The NMR spectra are similar for each series of triorganotelluronium halides (1–3, 4–6 and 7–9, respectively) and no clear evidence for N→Te interactions in solution could be concluded at room temperature, except in the case of compounds 4–6 for which the 1H resonance of the CH2N protons in the pendant arms appears as an AB spin system. For compounds 7 and 10 the low temperature 1H and 13C NMR spectra are consistent with intramolecularly coordinated pendant arms. The solid state structures for compounds 1, 1·0.5CH2Cl2, 3, 4·H2O, 5·H2O, 6, 7·H2O and 10 were determined by single-crystal X-ray diffraction. For all compounds the nitrogen atom of a pendant arm is involved in an intramolecular N→Te interaction in the range 2.571(3)–2.839(8) A. This results in hypercoordinated triorganotelluronium(IV) cations with different distorted coordination geometries: “see saw” in 1–3, square pyramidal in 4–6 and 10, and octahedral in 7. Further secondary interactions between cations, anions and water molecules were observed in the crystals of these species, resulting in different supramolecular associations.

The triarylphosphanes P(C6H4CH2NEt2-2)nPh3-n [n = 1 (1), 2 (2)] were obtained by reacting Ph2PCl or PhPCl2 with [2-(Et2NCH2)C6H4]Li in a 1:1 and a 1:2 molar ratio, respectively. Further oxidation with elemental sulfur or elemental selenium powder resulted in the triorganophosphane chalcogenides EP(C6H4CH2NEt2-2)nPh3-n [E = S, n = 1 (3), 2 (5); E = Se; n = 1 (4), 2 (6)]. The copper(I) complexes [CuCl{P(C6H4CH2NEt2-2)nPh3-n}] [n = 1 (7), 2 (8)] were prepared by the reactions between the triarylphosphanes 1 and 2 with CuCl in a 1:1 molar ratio. The new species were investigated in solution by NMR spectroscopy. The single crystal X-ray diffraction studies revealed a monomeric structure for the triorganophosphane sulphides 3 and 5, while the copper(I) complexes 7 and 8 form dimers by bridging chlorine atoms. In both copper complexes the phosphane ligands behave as C,N chelating moieties. For compound 8 the two C6H4CH2NEt2-2 groups are equivalent in solution, while in solid state only for one of them the N→Cu intramolecular interaction was observed.

Diorganodichalcogenides of type [2-(C6H5O)C6H4]2E2 [E S (1), Se (2), Te (3)] were prepared and structurally characterized by multinuclear NMR (1H, 13C, 77Se or 125Te, as appropriate) and ESI+ mass spectrometry. The oxidation reaction of the diorganodichalcogenides 2 and 3 with SO2Cl2 under anhydrous conditions led to the phenoxaselenine 10,10-dichloride (5) and to the organotellurium trichloride, [2-(C6H5O)C6H4]TeCl3 (4), respectively. Further hydrolysis with a KOH solution led to a mixture of phenoxachalcogenine 10-oxide [chalcogen = Se (7), Te (8)] and phenoxachalcogenine [chalcogen = Se (9), Te (10)] in each case. The crystal and molecular structures of compounds 2–5 and 7 were determined by single-crystal X-ray diffraction.

Cobalt(II) complexes of type [Co{(XPR2)(O2SR′)N}2] [X = S; R = Ph; R′ = Me (1), Ph (2), C6H4CH3-4 (3); X = O; R = Ph, R′ = Ph (4), R = OEt, R′ = C6H4CH3-4 (5)] were prepared by salt metathesis reactions between CoCl2·6H2O and the potassium salt of the appropriate organophosphorus acid in a 1:2 M ratio. All compounds were characterized by UV–Vis spectroscopy in CH2Cl2 solutions, mass spectrometry, infrared spectroscopy and room temperature magnetic susceptibility. For compounds 1 and 5 electronic spectra were recorded in dimethylformamide (dmfa) as well. While the electronic spectra suggest a monomeric structure in CH2Cl2 solutions with a tetrahedral environment about cobalt(II), for compound 3 in solid state a dinuclear structure was determined by single-crystal X-ray diffraction, with two bridging S,O,O-bimetallic triconnective and two S,O-monometallic biconnective [(SPPh2)(O2SC6H4CH3-4)N]− ligand units. From a CH2Cl2 solution of 1 crystals of the oxidation product [Co(OH){(SPPh2)(O2SMe)N}2] (6) were isolated after standing for several weeks in open atmosphere. Compound 4 in dimethylformamide decomposed and formed the octahedral species [Co(O2PPh2)2(HO2PPh2)2(dmfa)2] (7) (dmfa = dimethylformamide). The redox behavior of 1 was investigated by cyclic voltammetry in CH2Cl2 solution.

New diorganopnicogen(III) compounds of type [CH3OCH2CH2N(CH2C6H4)2]ML (M = Sb, L = ONO2 (3), OSO2CF3 (4); M = Bi, L = ONO2 (5), OSO2CF3 (6), OSO2C6H4(CHCH2)-4 (7) based on a heterocyclic butterfly-like tetrahydro-dibenzo[c,f][1,5]azastibocine/azabismocine skeleton were prepared by ligand exchange reactions between [CH3OCH2CH2N(CH2C6H4)2]MX (M = Sb, X = Cl (1); M = Bi, X = Br (2) and the appropriate silver salt. The new compounds 1 and 3–7 were structurally characterized by NMR and IR spectroscopy. For compounds 5, 7‧CHCl3 and the hydrolysis product [{CH3OCH2CH2N(CH2C6H4)2}BiOH2][CF3SO3] (6h) the crystal and molecular structures were determined by single-crystal X-ray diffraction. Strong transannular N→Bi interactions accompanied by strong MeO→Bi intramolecular interactions result in hypercoordinated species: 14‒Bi‒6 in 5, with a unisobidentate ONO2 ligand, and 12‒Bi‒5 in the cation of 6h and in 7‧CHCl3, with a monodentate OSO2C6H4(CHCH2)-4 ligand. The molecules are associated in dimeric units by Bi⋯π arene interactions (approx. 3.50 A). Weak H⋯O (in 5), H⋯π arene (in 7‧CHCl3), H⋯π arene, H⋯O and H⋯F (in 6h) intermolecular interactions contribute to supramolecular networks in all three compounds.

Several new diorganobismuth(III) compounds based on a butterfly-like tetrahydro-dibenzo[c,f][1,5] thiabismocine heterocyclic framework were prepared and structurally characterized. The reaction between the dilithio derivative of bis(2-bromobenzyl)sulfane with BiBr3 in a 1:1 M ratio resulted in the formation of [(C6H4CH2)2S]BiBr (1). Further exchange reactions of 1 with KI, AgNO3 and AgOSO2CF3, respectively, afforded the hypervalent species [(C6H4CH2)2S]BiX [X = I (2), ONO2 (3) and OSO2CF3 (4)]. The new species were characterized by 1H and 13C NMR, FT IR spectroscopy and mass spectrometry. The crystal and molecular structures of compounds 1–4 were determined by single-crystal X-ray diffraction. In all compounds the sulfur atom is strongly intramolecularly coordinated to bismuth, thus resulting in hypervalent species 10-Bi-4 (for 1 and 2) and 12-Bi-5 (for 3 and 4). Intermolecular interactions (X…Hmethylene in 1 and 2, Bi…Cg in 3 and Bi…O in 4) led to polymeric chains in the crystals. DFT calculations were carried out on [(C6H4CH2)2S]BiCl and 1–4 in order to better understand the S→Bi intramolecular coordination.

Bis(2-acetylphenyl)dichalcogenides of type [2-(O=CMe)C6H4]2E2 (E=S, Se, Te) were prepared by the hydrolysis of [2-{(CH2O)2C(CH3)}C6H4]2E2. In their reaction with benzylamine these species yield an air-sensitive condensation product, which undergoes a fast, unexpected oxidative intramolecular cyclization. This process proved to be a very convenient way to prepare 3-amino substituted benzo[b]chalcogenophenes. By contrast, the reaction between [2-(O=CMe)C6H4]TeCl and benzylamine resulted in the condensation product [2-(C6H4CH2N=CMe)C6H4]TeCl.

Tri- and diorganotin(IV) pseudohalides of type [2-(Me2NCH2)C6H4]R2Sn(NCE) [E = S, R = Me (1); E = Se, R = Me (2), Ph (3)] and respectively [2-(Me2NCH2)C6H4]RSn(NCE)2 [E = S, R = nBu (4), Ph (5), 2-(Me2NCH2)C6H4 (6); E = Se; R = 2-(Me2NCH2)C6H4 (7)] were obtained by reacting the appropriate organotin(IV) chlorides and alkali metal pseudohalides in stoichiometric amounts. The new species were characterized by multinuclear NMR (1H, 13C, 119Sn and 77Se where appropriate), IR spectroscopy and mass spectrometry. Both the 119Sn NMR and the X-ray diffraction studies evidenced the formation of Sn–NCE bonds in these compounds. For compounds 1–4, 6 and 7 the single-crystal X-ray diffraction studies revealed intramolecular Me2N→Sn interactions and the formation of hypervalent species 10-Sn-5 in compounds 1–3 and 12-Sn-6 in 4, 6 and 7, respectively. Compounds 1–3 are monomeric species, with monodentate isochalcogenocyanato ligands, while in 4 one of the NCE− ligands behave as a bridging moiety, thus resulting in dimeric associations. Short π CHγ-CH2⋯Cg and respectively Cg⋯Cg intermolecular contacts resulted in polymeric chains of dimmers in 4 and 3D supramolecular networks in 6 and 7, respectively. The reactions of [2-(Me2NCH2)C6H4]RSnCl2 and MECN in an 1:1 molar ratio resulted in the formation of a mixture of [2-(Me2NCH2)C6H4]RSnCl2, [2-(Me2NCH2)C6H4]RSn(NCE)2 and [2-(Me2NCH2)C6H4]RSnCl(NCE) [E = S, R = Ph (8), 2-(Me2NCH2)C6H4 (9); E = Se, R = 2-(Me2NCH2)C6H4 (10)].

Ligands of type [R2C(OH)CH2](2-Me2NCH2C6H4)E [R = Me, E = S (1), Se (2), Te (3); R = Ph, E = S (4), Se (5)] were obtained in the reactions of (2-Me2NCH2C6H4)ELi and the corresponding R2C(OH)CH2Cl (R = Me, Ph) reagent. The reactions between the ligands 1–3 and 5 with AgOTf (OTf = OSO2CF3), in a 1:1 M ratio, resulted in the silver(I) complexes [AgOTf{E[CH2C(OH)R2](C6H4CH2NMe2-2)}] [R = Me, E = S (6), Se (7), Te (8); R = Ph, E = Se (9)]. The new compounds 1–9 were investigated by solution NMR spectroscopy (1H, 19F, 77Se, 125Te, as appropriate). The ligands 1–5 were investigated also by 13C NMR. The IR spectra and the molar conductivity of the silver(I) complexes suggested a covalent nature of the Ag–OTf bond, while their ESI + MS spectra suggest the formation of dimeric species. Single crystal X-ray diffraction studies revealed a monomeric structure with intramolecular N⋯H–O hydrogen bonding for compound 5, while for the complex 6 dimeric associations formed by bridging ligands were found.

Several copper(I) complexes of type [CuXPPhn(C6H4CH2NMe2-2)3−n] [X = Cl, n = 1 (2), 2 (3); X = I, n = 0 (4), 1 (5), 2 (6)] were prepared by reacting CuX with the appropriate triarylphosphane in a 1:1 molar ratio. The ionic species [Cu(MeCN)2PPh2{C6H4CH2N(CH2CH2)2O-2}]+PF6− (7) was obtained in the reaction between [Cu(MeCN)4]PF6 and PPh2{C6H4CH2N(CH2CH2)2O-2} (1). All compounds were characterized by NMR spectroscopy (1H and 31P) and mass spectrometry. For compound 7 the 19F NMR spectrum was also recorded. Single-crystal X-ray diffraction studies put in evidence a P,N monometallic biconnective coordination behavior of the ligand in compounds 3, 6·0.5CH2Cl2 and 7·CH2Cl2, while in compound 4 a P,N,N monometallic triconnective behavior was observed. In species 2 the unit cell contains two independent molecules; in one of them the PN2 ligand behaves P,N,N-monometallic triconnective, while in the other as a P,N-monometallic biconnective moiety. The N→Cu intramolecular coordination induces planar chirality to the metal center and, as a consequence, the crystal contains both R and S isomers.

New enantiopure ligands containing two (–)-5,6-pinenebipyridine units connected by a bridge situated in position 6′ of the bipyridines have been prepared. The chemically addressable groups of the bridging (hydroxyl or keto) can be covalently bound to various supports in order to heterogenize the ligand.

Hypervalent diorganoselenium(II) compounds of type 1-{2-[(2-(3,5-dimethyl-4,5-dihydro-1H-pyrazol-1-yl)ethyl)selanyl]phenyl}-N,N-dialkylmethanamine, [2-(R2NCH2)C6H4][(3,5-dmpz)CH2CH2]Se, [R = Me (1), Et (2), dmpz = dimethylpyrazole] were obtained by reacting 1-(2-bromoethyl)-3,5-dimethyl-1H-pyrazole [(3,5-dmpz)CH2CH2Br] with alkali metal aryl selenolates of type [2-(R2NCH2)C6H4]SeM (R = Me, M = Na; R = Et, M = Li) in a 1:1 molar ratio. The coordination ability of species 1, as well as that of bis[2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl]selane, [(3,5-dmpz)CH2CH2]2Se (3) toward several late transition metals (Pd, Au, Ag) was investigated by reacting the neutral ligands 1 and 3 with PdCl2, AuCl(tht) and AgOTf in a 1:1 molar ratio. The neutral ligands 1–3, as well as the gold(I), silver(I) and palladium(II) adducts [2-(Me2NCH2)C6H4][(3,5-dmpz)CH2CH2)]SeAuCl (4), [(3,5-dmpz)CH2CH2)]2SeAuCl (5), [2-(Me2NCH2)C6H4][(3,5-dmpz)CH2CH2)]SeAgOTf (6), [(3,5-dmpz)CH2CH2)]2SeAgOTf (7) and [(3,5-dmpz)CH2CH2)]2SePdCl2 (8) were characterized by NMR spectroscopy (1H, 13C, 77Se) and mass spectrometry. The reaction between 1 and PdCl2 in a 1:1 molar ratio resulted in the formation of a complex reaction mixture of which the species [2-(Me2NCH2)C6H4SePdCl]2 (9) and 1-(2-chloroethyl)-3,5-dimethyl-1H-pyrazole [(3,5-dmpz)CH2CH2Cl] were unambiguously identified. Single crystal X-ray diffraction studies revealed a monomeric structure with a distorted T-shaped coordination geometry of type (C,N)SeC for the neutral ligand 1 and supramolecular associations based on dimeric units in case of species 9 and 9·0.5CH2Cl2·0.5THF.

Several organophosphorus acids of type [{XP(OEt)2}(O2SR)]NH [X = O, R = Me (1), Ph (2), C6H4CH3-4 (3); X = S, R = C6H4Cl-4 (4)] were obtained by a method based on the reaction between (EtO)2P(X)NHLi and the corresponding organosulfonyl chloride. They were subsequently deprotonated with KOBut. Salt metathesis reactions between PdCl2 and the corresponding potassium salts K[{XP(OEt)2}(O2SR)N] [X = O, R = Me (5), Ph (6), C6H4CH3-4 (7); X = S, R = C6H4Cl-4 (8)] in a 1:2 molar ratio resulted in palladium(II) complexes of type Pd[{XP(OEt)2}(O2SR)N]2 [X = O, R = Me (9), Ph (10), C6H4CH3-4 (11); X = S, R = C6H4Cl-4 (12)]. In a similar way was obtained the palladium(II) complex Pd[(SPPh2)(O2SPh)N]2 (13), using the appropriate reagents. All compounds were characterized by multinuclear NMR (1H, 13C, 31P) and infrared spectroscopy. The potassium salts and the palladium complexes were investigated also by mass spectrometry. Single-crystal X-ray diffraction studies revealed a layered supramolecular assembly in case of acid 1, a monomeric structure for compound 4, while in case of compound 2 dimeric associations are formed in the solid state by NH⋯OP hydrogen bonding. A trans-S,N-coordination pattern of the organophosphorus ligand was found in the palladium complex 12. Moreover, short Cl⋯H contacts result in a polymeric [Pd[{SP(OEt)2}(O2SC6H4Cl-4)N]2]n chain.

The new organophosphorus proligand (OPPh2)(O2SMe)NR (R = C6H3Pri 2–2,6) (3) was prepared as a white crystalline solid by reacting the lithiated compound Li[Ph2P(O)NR] with MeSO2Cl in a 1:1 molar ratio. The precursor Ph2P(O)NHR (1), as well as its thio analogue Ph2P(S)NHR (2), were obtained in the reaction between the lithiated amine RNHLi and the corresponding organophosphorus chloride. All compounds were characterized by multinuclear (1H, 13C, and 31P) NMR spectroscopy. The molecular structures of 1–3 were established by single-crystal X-ray diffraction. A zigzag polymeric chain is formed in the crystals of 1 and 2 by hydrogen N–H···X (X = O, S) bonding, while the crystal of 3 contains discrete monomeric units with a syn–syn conformation of the O˭P(C)2–N–S(C)(˭O)2 skeleton. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

The reaction between gold(I) and silver(I) starting materials with anionic organophosphorus ligands of type [(SPPh2)(O2SR)N]- resulted in new group 11 complexes of the type [Au{(SPPh2)(O2SR)N}(tht)] (tht = tetrahydrothiophene), [Au{(SPPh2)(O2SR)N}(PPh3)], PPN[Au{(SPPh2)(O2SR)N}2] [PPN = bis(triphenylphosphine)iminium], [Ag{(SPPh2)(O2SR)N}] and [Ag{(SPPh2)(O2SR)N}(PPh3)] (R = Me, Ph, C6H4CH3-4). The new derivatives were structurally characterized by 1H and 31P NMR spectroscopy, as well as infrared and mass spectrometry. Single-crystal X-ray diffraction studies revealed monomeric structures for the gold(I) species [Au{(SPPh2)(O2SMe)N}(PPh3)] (4) and [Au{(SPPh2)(O2SC6H4Me-4)N}(PPh3)] (6), while a dimeric association was found for the silver(I) compound [Ag{(SPPh2)(O2SPh)N}(PPh3)]2·2CH2Cl2 (14·2CH2Cl2). The organophosphorus(V) ligand units have different coordination patterns, i.e. S-monometallic monoconnective in 4, S,O-monometallic biconnective in 6 and S,S,O-bimetallic triconnective in 14, respectively. © 2009 Elsevier B.V. All rights reserved., Financial support from the Ministry of Education and Research of Romania (CNCSIS, Research Project No. 1456/2007-2008) is greatly appreciated. A.P. is grateful for a research fellowship awarded by the ‘‘Babes-Bolyai” University, Cluj-Napoca, Romania.

The complexes [Me 2 (MNAB)SnOSn(MNAB)Me 2 ] 2 ( 2 ) and [Me 2 Sn(MNAB) 2 ] ( 3 ), where HMNAB is 2-(2-methyl-3-nitroanilino)benzoic acid, ( 1 ), have been prepared and structurally characterized by means of vibrational, 1 H and 13 C NMR spectroscopies. The crystal structure of [Me 2 (MNAB)SnOSn(MNAB)Me 2 ] 2 has been determined by X-ray crystallography. Three distannoxane rings are present to the dimeric tetraorganodistannoxane of planar ladder arrangement. The structure is centro-symmetric and features a central rhombus Sn 2 O 2 unit with two additional tin atoms linked at the O atoms. Six-coordinated tin centers are present in the dimmer distannoxane. This structure is self-assembled in one dimensional infinite chain via intermolecular hydrogen bonds, π → π and C–H → π stacking interactions. The polar imino hydrogen atom participates in intramolecular hydrogen bonds. The catalytic activity of the prepared complexes in transesterification reactions has been studied. The diorganotin complexes efficiently catalyze the transesterification reaction of 2-phenylethanol without addition of free ligand or any promoting additive.

Nickel(II) complexes of the type Ni [ ( XPR 2 ) ( YPR 2 ′ ) N ] 2 [X = S ( 1 ) or O ( 2 ), Y = O, R = Ph, R′ = OEt] and Ni 2 [(OPPh 2 ) 2 N] 4 ( 3 ) were prepared by reacting either anhydrous NiCl 2 or NiCl 2 · 6H 2 O with the potassium salt of the appropriate tetraorganodichalcogenoimidodiphosphinic acid, in 1:2 molar ratio. Recrystallization of 3 from dimethylformamide resulted in Ni[(OPPh 2 ) 2 N] 2 (DMF) ( 4 ). Reaction between NiCl 2 and K[(SPPh 2 ){OP(OEt) 2 }N] in an 1:3 molar ratio resulted in the ionic species KNi[(SPPh 2 ){OP(OEt) 2 }N] 3 ( 5 ). Compounds 1 – 5 were characterized by IR, electronic spectroscopy and mass spectrometry. The molecular structures of 3 · CH 2 Cl 2 , 4 · 2H 2 O and 5 were determined by single-crystal X-ray diffraction. A dimeric structure was found in case of complex 3 · CH 2 Cl 2 , with both monometallic biconnective and homobimetallic triconnective [(OPPh 2 ) 2 N] − units, while an octahedral environment around nickel was established in the monomeric complex 4 · 2H 2 O by monometallic biconnective [(OPPh 2 ) 2 N] − and DMF ligands, respectively. The crystal of the ionic species 5 contains discrete tetranuclear units in which the phosphorus ligands act heterobimetallic, either ( O , O , S )-triconnective or ( S , O , O , O Et )-tetraconnective, and ( N , O , O , S )-heterotrimetallic tetraconnective, resulting in an octahedral environment around nickel and a square-pyramidal one around potassium, respectively. Powder X-ray diffraction studies on 5 are in agreement with the single-crystal investigation.

Cadmium complexes of the type Cd [ ( XPR 2 ) ( YPR 2 ′ ) N ] 2 ( X , Y = O , S ; R , R ′ = Me , Ph ) were obtained by reacting CdCl2 and K [ ( XPR 2 ) ( YPR 2 ′ ) N ] in a 1:2 molar ratio. The compounds were characterized by IR, multinuclear NMR (1H, 13C, 31P) spectroscopy and mass spectrometry. The molecular structures of Cd[(SPMe2)2N]2 (1), Cd[(OPMe2)(SPPh2)N]2 (4), [Cd2{(OPPh2)2N}4(H2O)] (7 · H2O) and K[Cd2{(OPPh2)2N}5] (8) were established by single-crystal X-ray diffraction. Colourless crystals of 8 were isolated, along with those of 7 · H2O, during recrystallization of crude Cd[(OPPh2)2N]2 (7). A monomeric structure with a tetrahedral CdS4 core is found for 1, whereas 4 contains discrete dimers formed through two O,O′, S-bimetallictriconnective ligand units resulting in distorted trigonal bipyramidal CdO3S2 cores. In the dinuclear compound 7 · H2O the Cd atoms are also bridged by two O,O′,O′-bimetallic triconnective ligands, but the coordination of the metal centres is completed by a bridging water molecule to givedistorted octahedral CdO6 cores. In the trimetallic unit of 8 the K atom is accommodated in the cavity described by the oxygen atoms of three ligand units which bridge the Cd atoms. The remaining two ligands are each one chelating a Cd atom, thus resulting in distorted square pyramidal CdO5 cores.

The cleavage of the Se–Se bond in [2-(Me2NCH2)C6H4]2Se2 (1) was achieved by treatment with SO2Cl2 (1:1 molar ratio) or elemental halogens to yield [2-(Me2NCH2)C6H4]SeX [X = Cl (2), Br (3), I (4)]. Oxidation of 1 with SO2Cl2 (1:3 molar ratio) gave [2-(Me2NCH2)C6H4]SeCl3 (5). [2-(Me2NCH2)C6H4]SeS(S)CNR2 [R = Me (6), Et (7)] were prepared by reacting [2-(Me2NCH2)C6H4]SeBr with Na[S2CNR2] · nH2O (R = Me, n = 2; R = Et, n = 3). The reaction of 3 with K[(SPMe2)(SPPh2)N] resulted in isolation of [2-(Me2NCH2)C6H4]Se–S–PMe2 N–PPh2 S (8). The compounds were characterized by solution NMR spectroscopy (1H, 13C, 31P, 77Se, 2D experiments). The solid-state molecular structures of 2, 4–8 were established by single crystal X-ray diffraction. All compounds are monomeric, with the N atom of the pendant CH2NMe2 arm involved in a three-center-four-electron N⋯Se–X (X = halogen, S) bond. This results in a T-shaped coordination geometry for the Se(II) atom in 2, 4, 6–8. In 5, the Se(IV) atom achieves a square pyramidal coordination in the mononuclear unit. Loosely connected dimers are formed through intermolecular Se⋯Cl interactions (3.40 A); the overall coordination geometry being distorted octahedral. In all compounds hydrogen bonds involving halide or sulfur atoms generate supramolecular associations in crystals.

BuSnCl2[(OPPh2)(SPPh2)N] (1) and BuSnCl[(OPPh2)(SPPh2)N](2) (2) were prepared by reacting BuSnCl3 and K[(OPPh2)(SPPh2)N], in 1: 1 and 1: 2 molar ratios. The compounds were investigated in solution by multinuclear (H-1, C-13, P-31, Sn-119) NMR spectroscopy. Variable-temperature P-31 NMR studies indicate dynamic behaviour in solution. The solid-state molecular structure was established by single-crystal X-ray diffraction revealing 5- and 6-coordinated metal atoms in 1 and 2, respectively, as a result of the monometallic biconnective behaviour of the monothioimidodiphosphinato moieties. Preliminary results on the in vitro biological activity are reported.

[2-(Me2NCH2)C6H4]Se-S(S)PR2 [R = Ph (1), (OPr)-Pr-i (2)] were prepared by reacting [2-(Me2NCH2)C6H4](2)Se-2 with the appropriate disulfanes, [R2P(S)S](2). The compounds were characterized by multinuclear magnetic resonance (H-1, C-13, P-31). The molecular structures of 1 and 2 were determined by single-crystal X-ray diffraction. Both compounds are monomeric and the nitrogen atom of the pendent CH2NMe2 arm is strongly coordinated to the selenium atom. The organophosphorus ligands are monodentate, thus resulting in a T-shaped coordination geometry around selenium.

The Cu(I) complexes, (Ph3P)2CuL (L = [S2PMe2]-, [OSPR2]- (R = Me, Ph), [(XPR2)(YPR'2)N]- (X, Y, R, R' = O, O, Ph, Ph; O, S, Ph, Ph; O, S, OEt, Ph; S, S, Me, Me)) and Cu(II) complexes, CuL2 (L = [(XPR2)(YPR'2)N]- (X, Y, R, R' = O, O, Ph, Ph; O, S, Ph, Ph)), have been prepared. The Cu(I) derivatives were characterized by multinuclear NMR spectroscopy and in two cases by X-ray crystallography. (Ph3P)2Cu[S2PMe2] (1) crystallizes in the orthorhombic space group P212121 (No. 19) with cell parameters a = 9.782(2), b = 17.808(4), c = 20.216(4) Å, V = 3521(6) Å3 and Z = 4, and (Ph3P)2Cu[(OPPh2)2N] (4) in the triclinic space group P[Formula: see text] (No. 2) with cell parameters a = 9.8079(2), b = 12.9141(3), c = 22.5666(5) Å, α = 75.714(2), β = 79.465(2), γ = 68.2770(8)°, V = 2559.9(1) Å3 and Z = 2. In both cases the phosphorus ligands are bidentate, thus resulting in monomeric molecules that contain tetrahedral CuP2S2 and CuP2O2 cores. The molecular structures of two of the Cu(II) derivatives were also determined. Cu[(OPPh2)2N]2 (8) and Cu[(OPPh2)(SPPh2)N]2 (9) crystallize in the triclinic space group P[Formula: see text] (No. 2) with cell parameters a = 8.887(2), b = 10.739(2), c = 12.477(3) Å, α = 77.61(3), β = 76.15(5), γ = 79.46(3)°, V = 1118.3(4) Å3 and Z = 1 for 8, and a = 9.626(2), b = 14.151(3), c = 24.752(5) Å, α = 88.23(3), β = 79.93(3), γ = 89.77(3)°, V = 3181(1) Å3 and Z = 3 for 9. The molecule of Cu[(OPPh2)2N]2 (8) has a planar CuO4 core, while in Cu[(OPPh2)(SPPh2)N]2 (9) both planar and tetrahedral copper cores are observed in a ratio of 1:2.Key words: structure, copper, thiophosphinates, oxo- and thio-imidodiphosphinates

Organoantimony complexes of the type PhSbCl2-xLx and Me3SbL2(L = [(OPPh2)(XPPh2)N]−, X = O, S; x = 1,2) were prepared and investigated by means of IR and multinuclear (1H, 13C, 31P) NMR spectroscopy. The PhSb(Cl)L compounds exhibited a redistribution process to give PhSbL2 and PhSbCl2. The molecular structures of PhSb[(SPPh2)2N]2 and Me3Sb[(OPPh2)(SPPh2)N]2 were established by single crystal X-ray diffractometry.

Solid state monomeric structures with monometallic biconnective (bidentate) diphenylphosphinodithioato groups were found in Ph2Te(S2PPh2)2 (1) or [Ph3Te][S2PPh2] (2), while in the polymeric associations [Te2(S2PPh2)2]n (3) and [PhTeS(S)PPh2]n (4) bimetallic biconnective (bridging) and monodentate biconnective (bridging) patterns were established by X-ray diffractometry. [Te(S2PPh2)3]2 (5) exhibits an unusual dimeric structure, with both monometallic biconnective and bimetallic triconnective ligand units.

Tri- and diphenyllead(IV) diorganophosphinodithioates, PhnPb(S2PR2)4−n (n = 2 and 3; R = Me, Et, Ph) were prepared by reacting the corresponding organolead(IV) chloride with the sodium or ammonium salt of the phosphinodithioic acid. The title compounds were investigated by infrared, 1H and 31P NMR, and mass spectroscopy, and possible structures were proposed. The diphenyllead(IV) phosphinodithioates, Ph2Pb(S2PR2)2, undergo decomposition on standing or on moderate heating, the least stable being the ethyl derivative. The process was monitored by using 1H and 31P NMR spectroscopy, and a reaction pathway leading to Ph3PbS2PR2, Pb(S2PR2)2, and R2P(S)SPh was established.

Elimination of Me3SiCH2Br from (Me3SiCH2)3SbBr2 leads to (Me3SiCH2)2SbBr ( 1 ). Reaction of 1 with Mg in tetrahydrofuran gives [(Me3SiCH2)2Sb]2 ( 2 ). Complete exchange reactions of 2 with RTeTeR afford (Me3SiCH2)2 SbTeR ( 3 : R = Ph, 4 : R = p-Tol). [(Me3SiCH2)2Sb]2Te ( 5 ) is formed by insertion of Te into 2 or better by the reaction of 1 with Na2Te. Die Eliminierung von Me3SiCH2Br aus (Me3SiCH2)3SbBr2 fuhrt zu (Me3SiCH2)2SbBr ( 1 ). Die Reaktion von 1 mit Mg in Tetrahydrofuran ergibt [(Me3SiCH2)2Sb]2 ( 2 ). Durch vollstandige Austauschreaktionen von 2 mit RTeTeR wird (Me3SiCH2)2SbTeR ( 3 : R = Ph, 4 : R = p-Tol) synthetisiert. [(Me3SiCH2)2Sb]2Te ( 5 ) wird durch Insertion von Te in 2 oder besser durch Umsetzung von 1 mit Na2Te gebildet.