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The [2+2] compartmental macrocyclic complexes [Ln(H 2 -L)-(N0 3 )], where H 2 -L is the cyclic Schiff base, derived from the condensation of 2,6-diformyl-4-chlorophenol (H-L A ) or 2,6-diformyl-4-methylphenol (H-L B ) and N,N-bis(2-aminoethyl)-2-hydroxybenzylamine·3HCl (HA'·3HCl), contains a free N 3 0 3 coordination chamber and can act as a ligand toward an identical or a different lanthanide(III) ion and a d transition metal(II) ion to give the related f,f homodinuclear [Ln 2 (L)-(X) 2] and f,f' heterodinuclear [LnLn'(L)(X) 2 ] or d,f heterodinuclear [LnM(L)(X)] complexes. They have been characterized by ESEM-EDS, ESI-MS, and IR and 1 H and 13 C NMR spectroscopy. The X-ray single-crystal analysis of the [2+1] acyclic complex [Lu 2 (L') 2 ], derived from partial hydrolysis of the related [2+2] homodinuclear complex [Lu 2 (L)(Cl) 2 ], followed by the loss of one lutetium(III) ion with the free formyl groups turning into diacetal ones, is also reported.

The reactivity of the cyclic primary aliphatic amines cyclopropyl-, cyclopentyl- and cyclohexylamine with cis- and trans-[PtCl 2 (NCMe) 2 ], under the same experimental conditions, is compared. Whereas cis-[PtCl 2 (NCMe) 2 ] yields the neutral diamidine compounds, the reactions with trans-[PtCl 2 (NCMe) 2 ] take place either with addition or substitution processes yielding the neutral diamidine complexes trans-[PtCl 2 (Amidine) 2 ], the monocationic trans-[PtCl(Amine)(Amidine) 2 ]Cl and the dicationic trans-[Pt(Amine) 2 (Amidine) 2 ]Cl 2 salts. An NMR and ESI study indicate that the main species formed is the monocationic trans-[PtCl(Amine)(Amidine) 2 ]Cl complex. The X-ray structure of trans{PtCl 2 {N(H)=C(CH 3 )NHCHCH 2 CH 2 } 2 ] is reported and its supramolecular arrangement is described.

New copper(I) complexes containing the water soluble N-methyl-1,3,5-triaza-7-phosphaadamantane (mPTA) phosphine have been synthesized by ligand-exchange reactions starting from [Cu(CH(3)CN)(4)][BF(4)] or [Cu(CH(3)CN)(4)][PF(6)] precursors and (mPTA)X (X=CF(3)SO(3), I). Depending on the ligand counter ion, the hydrophilic [Cu(mPTA)(4)][(CF(3)SO(3))(4)(BF(4))] 3a and [Cu(mPTA)(4)][(CF(3)SO(3))(4)(PF(6))] 3c complexes or the iodine-coordinated [Cu(mPTA)(3)I]I(3)4 species were obtained respectively and fully characterized by spectroscopic methods. Single crystal structural characterization was undertaken for [Cu(mPTA)(3)I]I(3).H(2)O, 4.H(2)O, and [Cu(mPTA)(4)][(CF(3)SO(3))(2)(BF(4))(3)] .0.25H(2)O, 3b.0.25H(2)O, the latter obtained by crystallization of [Cu(mPTA)(4)][(CF(3)SO(3))(4)(BF(4))] 3a. The cytotoxicity of analogous tetrahedral homoleptic Cu(I) derivatives [Cu(PTA)(4)](BF(4)) 1, [Cu(PTAH)(4)][Cl(4)(BF(4))] 2, [Cu(mPTA)(4)][(CF(3)SO(3))(4)(BF(4))] 3a and [Cu(mPTA)(4)][(CF(3)SO(3))(4)(PF(6))] 3c was evaluated against a panel of several human tumor cell lines. All the complexes showed in vitro antitumor activity comparable to that of the reference metallodrug cisplatin. Tests performed on cisplatin sensitive and resistant cell lines showed that against human ovarian 2008/C13(*) cell line pair, the resistance factor of copper derivatives was roughly 7-fold lower than that of cisplatin, whereas against human cervix cancer A431/A431-Pt cell line pair it was about 2.5-fold lower. These results, confirming the circumvention of cisplatin resistance, support the hypothesis that phosphine copper(I) complexes follow different cytotoxic mechanisms than do platinum drugs.

The new sodium bis(1-methyl-1 H -imidazol-2-ylthio)acetate, Na[( S -tim) 2 CHCO 2 ], has been prepared in ethanol solution using 2-mercapto-1-methylimidazole, dibromoacetic acid and NaOH. New di- and tri-organotin(IV) derivatives have been synthesized from reaction between SnR n Cl 4− n (R = Ph, Cy and n Bu, n = 2–3) acceptors and Na[( S -tim) 2 CHCO 2 ]. Complexes of the type {[κ 1 O -( S -tim) 2 CHCO 2 ]SnR 3 } and related decarboxylated species {[κ 2 N , N -( S -tim) 2 CH 2 ]SnR 2 Cl 2 } have been obtained and characterized by elemental analyses, FT-IR, ESIMS and multinuclear ( 1 H, 13 C and 119 Sn) NMR spectral data. The adduct {κ 1 O -[( S -tim) 2 CHCO 2 ]Sn(H 2 O)(C 4 H 9 ) 3 } was characterized by single crystal X-ray studies. The dichloromethane reaction solution of {κ 1 O -[( S -tim) 2 CHCO 2 ]Sn(C 6 H 5 ) 3 } was re-crystallized and the decarboxylated species {[( S -tim) 2 CH 2 ]SnCl(H 2 O)(C 6 H 5 ) 3 } was obtained as a crystalline solid and characterized by X-ray crystallography.

New silver(I) complexes have been synthesised from the reaction of AgNO3, monodentate PR3 (PR3 = P(o-tolyl)3, P(m-tolyl)3, P(p-tolyl)3, P(p-C6H4F), SeP(C6H5)3) or bidentate tertiary (dppe = bis(diphenylphosphane)ethane, dppf = 1,1′-bis(diphenylphosphane)ferrocene) phosphanes and potassium dihydrobis(3-nitro-1,2,4-triazolyl)borate, K[H2B(tzNO2)2]. These compounds have been characterized by elemental analyses, FT-IR, ESI-MS and multinuclear (1H and 31P) NMR spectral data. The adduct {[H2B(tzNO2)2]Ag[P(m-tolyl)3]2} has been characterized by single crystal X-ray studies. In the former, the H2B(tzNO2)2 acts as a monodentate ligand utilizing the coordinating capability of only one of the additional (exo-) ring nitrogens to complete the coordination array about the silver atom.

The new sodium bis(2-pyridylthio)acetate ligand, Na[(pyS) 2 CHCO 2 ], has been prepared in ethanol solution using 2-mercaptopyridine, dibromoacetic acid and NaOH. New mono- and di-organotin(IV) derivatives containing the anionic bis(2-pyridylthio)acetate have been synthesized from reaction between SnR n Cl 4− n (R = Me, Ph and n Bu, n = 1–2) acceptors and Na[(pyS) 2 CHCO 2 ]. Mono-nuclear complexes of the type {[(pyS) 2 CHCO 2 ]R n SnCl 4− n −1 } have been obtained and characterized by elemental analyses, FT-IR, ESI-MS, multinuclear ( 1 H and 119 Sn) NMR spectral data and X-ray crystallography. ESI-MS spectra of methanol solution of the complexes show the existence of hydrolysed species. Attempts to crystallize the dimethyltin(IV) derivative ( 3 ), from acetonitrile solution yield the dimeric dicarboxylatotetramethyldistannoxane ( 8 ), which was characterized by single crystal diffraction analysis.

2-(Azidomethyl)phenyl isocyanide, 2-(CH2N3)C6H4NC (AziNC), coordinates to some cationic Pt(II) and Pd(II) species to afford isocyanide complexes of the type trans-[MCl(AziNC)(PPh3)2][BF4] (M=Pt, l; Pd, 2). AziNC is coordinated also in some neutral Pt(II) and Pd(II) species such as [MCl2(AziNC)2] (M=Pt, 3; Pd, 4) derived from the reactions of 2 equiv. of AziNC with [PtCl2(COD)] and [PdCl2(MeCN)2], respectively. Complexes 1 and 2 react with 1 equiv. of PPh3 affording the heterocyclic carbene complexes trans-[MCl{ (H)}(PPh3)2][BF4] (M=Pt, 5; Pd, 6). Complexes 3 and 4 react with 1 equiv. of PPh3 displacing the isocyanide with the formation of the complexes cis-[MCl2(AziNC)(PPh3)] (M=Pt, 7; Pd, 8). These latter ones react with 2 equiv. of PPh3 affording as the final products the cationic carbene species trans-[MCl{ (H)}(PPh3)2][Cl] (M=Pt, 9; Pd, 10). Complex 5 was also characterized by single crystal X-ray diffraction. The carbene complex is square-planar and the angle formed between the platinum square plane and the heterocyclic carbene ligand is 87.9(2)°. The C(1)–N(1) and C(1)–N(2) bond distances in the latter of 1.32(2) and 1.30(2) A, respectively, are short for a single bond and indicate extensive π-bonding between the nitrogen atoms and the carbene carbon.

An improved synthesis of platinum acetate is reported in detail. This tetrameric complex reacts with PPh3 or P � /n-Bu3 at room temperature to give the thermodynamically unstable bis-substituted trans -[Pt(OAc)2L2] complexes, which are not easily accessible via other routes. The structure of the new compound trans -[Pt(OAc)2(PPh3)2] has been determined by X-ray analysis. # 2003 Elsevier B.V. All rights reserved.

The new η 2 -formamidinyl Zr complex Zr(NMeCyc) 2 [C(NAr)NMeCyc] 2 (1) (Ar = 2,6-dimethylphenyl, Cyc = cyclohexyl) was prepared upon double insertion of 2,6-dimethyl phenyl isocyanide in the Zr-N bond of Zr(NMeCyc) 4 . 1 wasthen converted into Zr(OC 6 F 5 ) 2 [C(NAr)N-MeCyc] 2 (2) and ZrCl 2 [C(NAr)NMeCyc] 2 (3) by reacting it with C 6 F 5 OH and [NHMe 3 ]Cl, respectively. The crystal structure of 1 was established by X-ray analysis. All the complexes have been tested as catalysts for the polymerization of ethylene and 1-hexene in the presence of [NHMe 2 Ph][B(C 6 F 5 ) 4 ] as cocatalyst.

The synthesis and the X-ray structure of the two pseudotetrahedral Zn(II) zwitterionic complexes: trichloro(1-methylpiperazin-1-ium-N4)zinc(II), [ZnCl3(H2Meppz)], and trichloro(1,4-dimethylpiperazin-1-ium-N4)zinc(II), [ZnCl3(HMe2ppz)], are described [(H2Meppz)+=1-methylpiperazin-1-ium monocation and (HMe2ppz)+=1,4-dimethylpiperazin-1-ium monocation]. [ZnCl3(H2Meppz)] and [ZnCl3(HMe2ppz)] complexes are isomorphous and isostructural, respectively, to the [CoCl3(H2Meppz)] and [CoCl3(HMe2ppz)] complexes, already reported in literature by us. Both complexes present a very uncommon and distorted tetrahedral aminotrichlorozinc(II), NZnCl3, group, where N is a nitrogen atom of an aliphatic amine. So far this group has been found only in the (1,3,5,7-tetraazaadamantane)trichloro-zincate(II) anion [{(CH2)6N4}ZnCl3]−. The bulky ZnCl3 group present in [ZnCl3(HMe2ppz)], is coordinated to the axial position of the piperazine ring instead of the less hindered equatorial position, as found in the analogous [CoCl3(HMe2ppz)] complex. An extended hydrogen bond network is present in the crystals of both the complexes but, while the [ZnCl3(H2Meppz)] complex shows nearly linear N+H⋯Cl intermolecular hydrogen bonds, the [ZnCl3(HMe2ppz)] complex shows a perfectly symmetrical (imposed by space group symmetry) Download : Download full-size image ZnNCl three-centre intermolecular hydrogen bond. The solid state infrared spectra of both the compounds are discussed in agreement with the hydrogen bond network present in the crystals.

Lanthanide(III) complexes of six-nitrogen-donor macrocyclic ligands carrying a benzyl-type group, CH2C6H4X (X=H, OH, or NH2), at each di-imine side chain were synthesized by the metal-templated, cyclic Schiff-base condensation of 2,6-diacetylpyridine with substituted S- or R,S-1,2-diaminopropanes. The complexes were obtained as mixtures of constitutional isomers and stereoisomers, which were identified by 1H NMR spectra and separated by fractional crystallization. The molecular structure of the 11-coordinate complex [La(NO3)2(H2O)(C36H38N6)](NO3)(H2O) was established by X-ray crystallography.

The reactions of cis-[PtCl2(NCMe)2] with a fivefold excess of the primary aliphatic amines RNH2 (R=Me, Et, Pri, But) in CH2Cl2 at −10 °C afford in high yield the bis-amidine complexes cis-[PtCl2{ZN(H)C(NHR)Me}2], where both amidine ligands assume the Z configuration. The corresponding reactions of trans-[PtCl2(NCMe)2] with RNH2 (R=Me, Et, But) give a mixture of the bis-amidine trans-[PtCl2{ZN(H)C(NHR)Me}2] and the mono-amidine trans-[PtCl2(NCMe){ZN(H)C(NHR)Me}] derivatives, which could be isolated as pure products operating with a platinum nitrile complex:amine molar ratio of 1:50 or 1:1, respectively. The reaction of trans-[PtCl2(NCMe)2] with a 50-M excess of PriNH2 affords the bis-amidine bis-amine dicationic complex trans-[Pt(H2NPri)2{ZN(H)C(NHPri)Me}2]Cl2, which has been characterized also by X-ray diffraction analysis. The reactions of cis- and trans-[PtCl2(NCMe)2] with the secondary aliphatic amines R′R″NH yield the bis-amidine complexes cis- and trans-[PtCl2{EN(H)C(NR′R″)Me}2] (R′, R″=Et) and/or cis- and trans-[PtCl(NCMe){EN(H)C(NR′R″)Me}2] (R′, R″=Et; R′=Me, R″=But), where the amidine ligands have the E configuration. The compound trans-[PtCl2(NCMe){EN(H)C(NMeBut)Me}] has been characterized by single crystal X-ray diffraction. All the complexes have been characterized by IR, 1H and 13C NMR spectroscopies. The Z or E configuration of the amidine ligand can be readily deduced by 1H NMR data.

Complexes of Ca(II) and Sr(II) with six-nitrogen-donor macrocyclic ligands carrying a methyl group at each diimine side-chain were synthesized by the metal-templated condensation of 2,6-diacetylpyridine with R-, S-, or R,S-1,2-diaminopropane. The complexes exist as stereoisomers as well as constitutional isomers, which can be identified by 1H NMR spectra and separated by fractional crystallization. The molecular structure of the eight-coordinate complex [Sr(CF3SO3)2(C24H30N6)] was established by X-ray crystallography.

The reaction of cis-[PtCl2(NCMe)2] with a 5-fold excess of Me2NH in CH2Cl2 at −10°C affords in high yield the bis-amidine complex cis-[PtCl2{E-N(H)C(NMe2)Me}2] (E,E-2), where both the amidine ligands assume the E configuration. E,E-2 was characterized by X-ray structure analysis, NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). The corresponding reactions of trans-[PtCl2(NCMe)2] with Me2NH gave the bis-amidine complex trans-[PtCl2{E-N(H)C(NMe2)Me}2] (E,E-3) and the mono-amidine derivative trans-[PtCl2{E-N(H)C(NMe2)Me}(NCMe)] (E-4).

The complexes trans-[FeH(NCR)(dppe)2][BF4] (1) (R=NH2, NMe2, NEt2 or NC(NH2)2; dppe=Ph2PCH2CH2PPh2) and trans-[FeL(NCR)(depe)2]Yn (R=NH2, NMe2, NEt2 or NC(NH2)2; depe=Et2PCH2CH2PEt2; Y=BF4 or BPh4; (2), L=Br, n=1; (3), L=NCR, n=2) have been prepared by treatment of trans-[FeHCl(dppe)2] (in THF and in the presence of Tl[BF4]) or trans-[FeBr2(depe)2] (in MeOH and in the presence of [NBu4][BF4] or Na[BPh4]), respectively, with the appropriate cyanamide. NMR and Mossbauer spectral, as well as FAB mass spectrometric data are reported. Mossbauer partial isomer shift (PIS) and partial quadrupole splitting (PQS) parameters have been estimated for the cyanamide and dppe ligands and rationalised, with the overall IS and QS, in terms of π- and σ-electronic effects, the cyanamides behaving as more effective σ-donors and weaker π-acceptors than organonitriles. FAB MS fragmentation patterns are also proposed. The crystal structures of 1 (R=NH2) and 3 (R=NEt2, Y=BF4) are reported.

The crystal structures of two stereoisomers of tetraphenyl- and pentaphenyl-substituted cyclopentenes 1 and 2 have been determined by X-ray analysis. An envelope conformation 1E has been ascertained for the cis isomer 1a, whereas the cis, cis isomer 2a, which crystallizes in two different space groups, P1¯ and P21/n, displays a twisted 2T1 conformation. The phenyl substituents are all tilted with respect to the cyclopentene ring in both structures. Compound 1a crystallizes in the space group P21/a with a = 18.553(3), b = 6.006(2), c = 19.355(5), β = 102.67(4)°, and V = 2104.2(g) A3 for Z = 4; compound 2a I crystallizes in P21/n with a = 10.064(2), b = 20.756(5), c = 12.245(3) A, β = 95.21(2)°, and V = 2547(1) A3 for Z = 4; compound 2aII crystallizes in P1¯ with a = 10.117(3), b = 11.750(2), c = 12.359(2) A, α = 111.25(2), β = 94.84(2), γ = 108.78(2)°, and V = 1262.3(6) A3 for Z = 2.

3,3′-(1,2-ethanediyl)bis[2-substituted-1,3-thiazolidin-4-one] derivatives display different biological activities depending on the configuration of the 2,2′ centers and on the substitution at C2, C2′. In this context, 3,3′-(1,2-ethanediyl)bis[2-(2′-(5′-methyl)thienyl)-1,3-thiazolidin-4-one] (6b) and 3,3′-(1,2-ethanediyl)bis[2-(3′-pyridyl)-1,3-thiazolidin-4-one] (8b) have been prepared. Their structural and conformational features, which can be related to the biological activity, have been investigated by X-ray diffraction and molecular modeling techniques.

The cyanoguanidine complex cis-[Pt(NCNC(NH2)2)2(PPh3)2][BPh4]2, prepared by reacting cis-[PtCl2(PPh3)2] with cyanoguanidine in the presence of Na[BPh4], readily reacts with methanol to give cis-[(PPh3)2PtNHC(OMe) = NC(NH2) = NH)] [BPh4] containing a novel type of azametallcycle whose molecuar structure is established by X-ray crystallography. Its formation involves metal-promoted nucleophilic addition of the alcohol to the cyano group of a cyanoguanidine ligand, combined with deprotonation of the guanidine unit which then chelates the Pt(II) centre.

The cyclic five-membered platinum(II) oxycarbene complex trans-[Pt(Me){CCH(p-tolyl)CH2CH2O}(PPh3)2][BF4] (1) can be prepared in good yield under very mild conditions either by reaction of trans-[Pt(Me)(C⋮C-p-tolyl)(PPh3)2] with oxirane in the presence of 1 equiv of HBF4 or by reaction of the cationic solvato complex trans-[Pt(Me)(PPh3)2(solv)][BF4] with oxirane and 1.5 equiv of p-tolylacetylene. The X-ray crystal structure of 1 is reported.

In the β form of tris(thiocyanato-N)[2,7,13,18-tetramethyl-3,6,14,17,23,24-hexaazatricyclo[17.3.1.1 8,12 ]-tetracosa-1(23),2,6,8(24),9,11,13,17,19,21-decaene-N 3 ,N 6 ,N 14 ,N 17 ,N 23 ,N 24 ]europium, the nine-coordinate Eu III ion is bound to the N atoms of three monodentate isothiocyanate ligands and to the six N atoms of the macrocyclic ligand L (C 22 H 26 N 6 ), which has an 18-membered six-N-atom donor cavity, with a coordination geometry analogous to that of the α form.

The reactions of the nitrile complexes cis- and trans-[PtCl2(NCR)2] (R = Me, Et, CH2Ph, Ph) with an excess of ethanethiol, EtSH, in the presence of a catalytic amount of n-BuLi in tetrahydrofuran (THF), afforded in good yield the bis-imino thioether derivatives cis-[PtCl2{E-N(H)?C(SEt)R}2] (R = Me (1), Et (2), CH2Ph (3), Ph (4)) and trans-[PtCl2{E-N(H)?C(SEt)R}2] (R = Me (5), Et (6), CH2Ph (7), Ph (8)). The imino thioether ligands assumed the E configuration corresponding to a cis addition of the thiol to the nitrile triple bond. The spectroscopic properties of these complexes have been reported along with the molecular structures of 1, 2, and 7 as established by X-ray crystallography which indicated that these compounds exhibit square-planar coordination geometry around the platinum center. Four N-H···Cl intermolecular contacts (N-H···Cl ca. 2.5-2.7 Å) between each chlorine atom and the N-H proton of the imino thioether ligand gave rise to "dimers" Pt2Cl4L4 (L = imino thioether) formed by two PtCl2L2 units. The cytotoxic properties of these new platinum(II) complexes were evaluated against various human cancer cell lines. Among all derivatives, trans-[PtCl2{E-N(H)?C(SEt)CH2Ph}2] showed the greatest in vitro cytotoxic activity being able to decrease cancer cell viability roughly 3-fold more effectively than cisplatin.

The chloro complexes trans-[Pt(Me)(Cl)(PPh3)2], after treatment with AgBF4, react with 1-alkynes HCCR in the presence of NEt3 to afford the corresponding acetylide derivatives trans-[Pt(Me) (CCR) (PPh3)2] (R = p-tolyl (1), Ph (2), C(CH3)3 (3)). These complexes, with the exception of the t-butylacetylide complex, react with the chloroalcohols HO(CH2)nCl (n = 2, 3) in the presence of 1 equiv. of HBF4 to afford the alkyl(chloroalkoxy)carbene complexes trans-[Pt(Me) {C[O(CH2)nCl](CH2R) } (PPh3)2][BF4] (R = p-tolyl, n = 2 (4), n = 3 (5); RPh, n = 2 (6)). A similar reaction of the bis(acetylide) complex trans-[Pt(CCPh)2(PMe2Ph)2] with 2 equiv. HBF4 and 3-chloro-1-propanol affords trans-[Pt(CCPh) {C(OCH2CH2CH2Cl)(CH2Ph) } (PMe2Ph)2][BF4] (7). T alkyl(chloroalkoxy)-carbene complex trans-[Pt(Me) {C(OCH2CH2Cl)(CH2Ph) } (PPh3)2][BF4] (8) is formed by reaction of trans-[Pt(Me)(Cl)(PPh3)2], after treatment with AgBF4 in HOCH2CH2Cl, with phenylacetylene in the presence of 1 equiv. of n-BuLi. The reaction of the dimer [Pt(Cl)(μ-Cl)(PMe2Ph)]2 with p-tolylacetylene and 3-chloro-1-propanol yields cis-[PtCl2{C(OCH2CH2CH2Cl)(CH2C6H4-p-Me}(PMe2Ph)] (9). The X-ray molecular structure of (8) has been determined. It crystallizes in the orthorhombic system, space group Pna21, with a = 11.785(2), b = 29.418(4), c = 15.409(3) A, V = 4889(1) A3 and Z = 4. The carbene ligand is perpendicular to the Pt(II) coordination plane; the PtC(carbene) bond distance is 2.01(1) A and the short C(carbene)-O bond distance of 1.30(1) A suggests extensive electronic delocalization within the PtC(carbene)O moietry.

3,3′(1,2-Ethanediyl)bis(2-halophenyl-thiazolidin-4-one) derivatives display different pharmacological activities depending on the configuration of the 2,2′ centers and on the oxidation state of the sulfur atoms. Quantum-chemical calculations on the 3-fluorophenyl-substituted configurational isomers are reported here, together with the X-ray structure of the 1∶1 dioxide derivative. This crystallizes in the monoclinic space group P21/c, with four molecules per unit cell and cell dimensions:a=18.917(3),b=9.003(2),c=12.062(2)A, β=96.20(3)°. The compound, which has an approximate center of symmetry in the middle of the ethylene chain and two asymmetric carbon atoms of opposite chiralities, is the (2R,2′S-meso) (or 2S,2′R-meso) stereoisomer.

The title complex was prepared by reacting Pd(AcO) 2 first with dppp and then with TsOH·H 2 O in MeOH at r.t. It is highly active in COC 2 H 4 copolymerization in MeOH. It has been characterized by IR and 1 H and 31 P NMR spectroscopies. The X-ray structure consists of a packing of monomeric palladium cations and tosylate anions in the ratio 1:1. The palladium atom is in rather distorted square coordination.

The 1,3-oxazine complexes cis- and trans-[PtCl2{ N C(R)OCH2CH2C}H22] (cis: RCH3 (1a), CH2CH3 (2a), (CH3)3C (3a), C6H5 (4a); trans:R CH3 (1b), C6H5 (4b)) were obtained in 51-71% yield by reaction in THF at 0 °C of the corresponding nitrile complexes cis- and trans-[PtCl2(NCR)2] with 2 equiv. of −OCH2CH2CH2Cl, generated by deprotonation of 3-chloro-1-propanol with n-BuLi. The cationic nitrile complexes trans-[Pt(CF3)(NCR)(PPh3)2]BF4 (RCH3, C6H5) react with 1 equiv, of − OCH2CH2CH2Cl to give a mixture of products, including the corresponding oxazine derivatives trans-[Pt(CF3){ NC(R)OCH2CH2C CH2}(PPh3)2]BF4 (5 and 6), the chloro complex trans- [Pt(CF3)Cl(PPh3)2] and free oxazine NC(R)OCH 2 CH 2 C H2. For short reaction times (c. 5–15 min) the oxazine complexes 5 and 6 could be isolated in modest yield (37–49%) from the reaction mixtures and they could be separated from the corresponding chloro complex (yield 40%) by taking advantage of the higher solubility of the latter derivative in benzene. For longer reaction times (> 2 h), trans-[Pt(CF3)Cl(PPh3)2] was the only isolated product. Complex 6 was crystallographically characterized and it was found to contain also crystals of trans- [PtCl{ NC(R)OCH 2 CH 2 C H2}(PPh3)2]BF4, which prevented a more detailed analysis of the bond lengths and angles within the metal coordination sphere. The 1,3-oxazine ring, which shows an overall planar arrangement, is characterized by high thermal values of the carbon atoms of the methylene groups indicative of disordering in this part of the molecule in agreement with fast dynamic ring processes suggested on the basis of 1H NMR spectra. It crystallizes in the trigonal space group P 3 , with a=22.590(4), b=15.970(3) A, γ=120°, V=7058(1) A3 and Z=6. The structure was refined to R=0.059 for 3903 unique observed (I⩾3σ(I)) reflections. A mechanism is proposed for the conversion of nitrile ligands to oxazines in Pt(II) complexes.

The stereochemistry of the 3,3′-(1,2-ethanediyl)bis[2-(3-fluorophenyl)-1,3-thiazolidine-4-one] configurational isomers ( 2R,2′R 2S,2′ S and 2R,2′S meso ) has been investigated by 1 H-NMR techniques in solution, by X-ray diffraction methods in the solid state and by quantum chemical methods as the free molecule. The racemic compound, which has antagonistic activity at both H 1 and H 2 receptors, is found to prefer a gauche conformation in CDCl 3 solution, in the solid state and in the free molecule. The inactive meso stereoisomer is centrosymmetric in the crystalline state with an antiperiplanar conformation of the ethylene chain, whereas in CDCl 3 solution it exists as a rapidly interconverting mixture of 3 rotamers. The free molecule presents 2 gauche and 1 anti -periplanar conformations (differing by 1.3–2.4 kcal/mol). Some relationships between stereochemistry and activity are discussed.

Yellow crystals of formula [La(CH3COO)(NCS)2(C26H18N6)] were synthesized by the condensation of 1,2-diaminobenzene and 2,6-pyridinedicarboxyaldehyde in the presence of lanthanum(III) acetate, followed by partial acetate-thiocyanate metathesis. The complex has been characterized by X-ray crystallography. The LaIII ion is 10-coordinate, being linked to the six nitrogen atoms of the macrocyclic ligand, to the nitrogen atoms of two isothiocyanates situated on opposite sides of the macrocycle and to a bidentate chelating acetate. The IR and NMR spectra (1H and 13C) of the complex were recorded and assigned.

Single-crystal X-ray work has been carried out on the 2-benzyl-5-cyano-1,6-dihydro-6-oxo-3-methoxycarbonyl pyridine compound 1f. It crystallizes in the triclinic system space group P 1 . Minimum energy conformations of 2-(alkyl or arylalkyl) 5-cyano-1,6-dihydro-6-oxo-3-pyridine carboxylates showing different biological activity have been calculated by the semiempirical MNDO and AM1 methods. A most critical factor for the different inotropic activities (positive or negative) of compounds 1a–1f seems to be related to the location and the steric requirements of a ‘pocket’ in the receptor boundary that limit the size of the substituent at position 2.

The synthesis of ethyl or methyl 4-substituted or unsubstituted 2-(dimethylamino)-5-pyrimidinecarboxylates 10-20, which is mainly carried out by reaction of ethyl or methyl 2-[(dimethylamino)methylene]-3-oxoalkanoates with 1,1-dimethylguanidine, is described. The above esters were hydrolyzed to the relative carboxylic acids 21-30, which were decarboxylated to the corresponding 2,4-disubstituted pyrimidines 31-40. All the new synthesized pyrimidines were evaluated in spontaneously beating and electrically driven atria from reserpine-treated guinea pigs. Their effects were compared to those induced by milrinone in both atria preparations. Compound 28 (4-benzyl-2-(dimethylamino)-5-pyrimidinecarboxylic acid) was the most effective positive inotropic agent, while the corresponding methyl ester 17 reduced both the contractile force and the frequency of guinea pig atria. An antagonism toward the negative influence exerted by endogenous adenosine on the heart seems to be involved in the contractile activity of compound 28. By contrast, compound 17 might be partial agonist at the purinergic inhibitory (A1) receptor. X-ray analysis carried out on 17 and 28 and molecular modeling investigations extended also to related derivatives allowed a possible rationalization between structure and inotropic activity for this series of compounds.

The reactions of cyclopropylamine, cyclopentylamine, and cyclohexylamine with trans-[PtCl2(NCMe)(2)] afforded the bis-cationic complexes trans-[Pt(amine)(2)(Z-amidine)(2)](2+)[Cl-](2), 1-3, The solution behavior and biological activity have been studied in different solvents (DMSO, water, polyethylene glycol (PEG 400), and polyethylene glycol dimethyl ether (PEG-DM E 500)). The biological activity was strongly influenced by the cycloaliphatic amine ring size, with trans-[Pt(NH2CH(CH2)(4)CH2)(2){N(H)=C(CH3)-N(H)CH(CH2)(4)CH2}(2)](2+)[Cl-](2) (3) being the most active compound. Complex 3 overcame both cisplatin and MDR resistance, inducing cancer cell death through p53-mediated apoptosis. Alkaline single-cell gel electrophoresis experiments indicated direct DNA damage, reasonably attributable to DNA adducts of trans-[PtCl(amine)(Z-amidine)(2)][Cl] species, which can evolve to produce disruptive and nonrepairable lesions on DNA, thus leading to the drug-induced programmed cancer cell death. Preliminary in vivo antitumor studies on C57BL mice bearing Lewis lung carcinoma highlighted that complex 3 promoted a significant and dose-dependent tumor growth inhibition without adverse side effects.

4,6-Dimethylbenzoangelicin, obtained by fusing a benzene ring at the furan side of 4,6-dimethylangelicin, was studied in terms of crystal structure and interactions with DNA in both ground and excited states. 4,6-Dimethylbenzoangelicin has a planar structure and forms a molecular complex with DNA, undergoing intercalation inside the double helix. Under UVA irradiation, it photoconjugates covalently with the macromolecule, showing a DNA photobinding rate slightly lower than that of 8-methoxypsoralen, involving however only its 3,4 double bond, i.e. behaving as a pure monofunctional agent. The parameters of dark binding and photobinding were determined, and two C4 cycloadducts with thymine were isolated and characterized.

The compounds Et2InNR2 (R  Me, Et, or SiMe3) and Et2InPyrr (HPyrr  pyrrole) have been prepared by reaction of Et2InCl with the corresponding lithium amide or pyrrolide in diethylether. Their 1H NMR, IR and mass spectra are reported and discussed. The amides are dimers in the vapour phase. Diethylindium bromide is a layer polymer. The octahedral coordination geometry of indium is characterized by four distinct InBr distances ranging from 2.777(2) to 3.848(2) A. Diethylindium pyrrolide has a chain structure as shown by the relatively short intermolecular interactions between each indium atom and the double bonds of two adjacent different pyrrole units (3.063(5) and 2.950(5) A, respectively). The indium coordination geometry is then trigonal bipyramidal, with the shortest bonds in the equatorial plane (InC(5) 2.143(5) A, InC(7) 2.141(5) A, InN 2.166(4) A).

The X-ray crystal structures of [Th(NCS) 4 (DIPIBA) 3 ] ( 1 ) [DIPIBA Me 2 CH CON(CHMe 2 ) 2 ] and [Th(NCS) 2 Cl 2 (DCA) 3 ]( 2 ) [DCA MeCON(cycloC 6 H 11 ) 2 ] have been determined from three-dimensional X-ray diffraction data. The different steric constraints of the ligand are not sufficient for different coordination geometries. In 1 and 2 the coordination polyhedron about the seven-coordinate thorium atom is a pentagonal bipyramid geometry which is becoming rather common for thorium(IV) compounds. In these compounds two chlorine ( 2 ) and two thiocyanate ( 1 ) anions are in axial positions with a significant shortening of the axial Th—NCS bonds with respect to the equatorial ones, while in the equatorial plane a neutral ligand lies between two anionic ligands, the remaining coordination positions being occupied by two other neutral ligands. The average bonding distances are Th O = 2.34(1)A, Th N ax = 2.42(1) and Th N eq = 2.46(1)Ain 1 , and Th O = 2.357(5), Th N eq = 2.479(6) and Th Cl ax = 2.695(3)Ain 2.

Complexes with formula [LnL8](ClO4)3 (LnLaHo) and [LnL7](ClO4)3 (LnErLu, Y; Lδ-valerolactam) were synthesized and characterized by conductance measurements, IR spectra, X-ray powder diffraction patterns, electronic absorption spectra of the neodymium and emission spectrum of the europium compounds. X-ray single crystal structural analysis of the neodymium compound showed that it forms monoclinic crystals, space group P21/n with a=25.491(4), b=16.074(3), c=13.051(3) A and β=90.15(3)°. Neodymium ions are coordinated in a square-antiprismatic arrangement to eight oxygen atoms of the δ-valerolactam ligands. The average NdO bond length is 2.45(1) A. The non-coordinated ClO4− ions are partially disordered.

The diaminocarbene complexes cis-Cl2(PPh3)Pt[ CN(Bu t )CH 2 CH 2 N H] (1) and cis-Cl2Pt[ CN(C 6 H 4 -p-OMe)CH 2 CH 2 N H]2 (2) have been prepared by reaction of the corresponding isocyanide derivatives with aziridine/ClCH2CH2NH3+Cl− and aziridine alone, respectively. The aminooxycarbene complex cis-Cl2Pt[ CN(C 6 H 4 -p-OMe)CH 2 CH 2 O ]2 (3) has been prepared by reaction of the bis-isocyanide derivative with 2-chloroethanol/n-BuLi. The dimeric complexes {(PPh3)BrPd[μ- CN(Me)CH 2 CH 2 N C,N]}2 (4), {(PPh3)ClPd[μ- CN (C6H4-p-OMe)CH2CH2NC,N]}2 (5), {(PPh3)ClPt[μ- CN(C 6 H 4 -p-OMe)CH 2 CH 2 N C,N]}2 (6) have been prepared by deprotonation reaction of the NH group of the corresponding mononuclear derivatives with n-BuLi. The X-ray structure of {(PPh3)ClPt[μ- COCH 2 CH 2 N C,N]}2 (7) is reported. The structural model was refined to R=0.055 (Rw=0.061) for 7442 independent reflections. Crystal data: triclinic, space group P , a=19.564(3), b=16.497(3), c=13.243(2) A, α=88.93(3), β=97.88(3), γ=91.97(3)° Z=4. The crystal contains two crystallographically independent dimer units and a disordered dichloroethane molecule. Each dimer is formed by two bridging carbene ligands which are coordinated to one platinum on one side via a PtN bond and to the second platinum via a PtC bond. The coordination geometry around each platinum atom is an irregular square with deviations in the tetrahedral direction of the bonded atoms. The anodic behaviour of these and related monocarbene, dicarbene or dinuclear dicarbene complexes has been studied by cyclic voltammetry and controlled potential electrolysis in aprotic media and shown to present irreversible oxidation waves commonly with a multi-electron character (up to four electrons) and involving liberation of protons (in a number similar to that of the transfered electrons) conceivably resulting from anodically induced NH or CH bond cleavage, the former at an amino group and the latter occurring at methylene groups activated by adjacent amino- or oxy-carbene moieties.

Reaction of the new disodium salt: Na2[2,6-C5H3N(CH2C5H4)2 (2; 2,6-C5H3N = 2,6-pyridyl) with UCl4 in THF affords the reddish-green, mononuclear Cp2UIVCl2-derivative (Cp  η5-C5H5): μ-{2,6-CH2C5H3NCH2}(η5-C5H4)2UIVCl2 (1. According to a single-crystal X-ray study, 1 involves a notably strong UN bond (UNav: 2.62(1) A) along with two nonequivalent Cl ligands (UCl: 2.615(3) and 2.636(3) A). The low-temperature 1H NMR spectrum of the paramagnetic complex is in full accord with the solid state structure 1. Up to room temperature, the dissolved molecules of 1 show no fluxionality on the NMR time scale, although the two CH2 proton resonances appear to undergo coalescence.

The crystal and molecular structures of two configurational isomers (hereinafter HM and LM) of the title compound have been determined from single-crystal X-ray diffraction data. The HM isomer has crystallographically imposed ¯1 symmetry; then, the two asymmetric carbon atoms must have opposite chirality and the product is the 2R2′S-meso (or 2S2/t'r-meso) stereoisomer. The ethylenediamine group assumes the anti-periplanar conformation, the two phenyl rings are strictly planar, and the two thiazolidine rings present the same envelope conformation. The LM isomer is characterized by a-syn-clinal conformation of the ethylenediamine group, by the same envelope conformation of the two thiazolidine rings, and by the same chirality of the two asymmetric carbons atoms. Nevertheless in the crystal structure both enantiomers, 2R2′R and 2S2′S, are present.

A series of complexes of formula ML 3 X 3 •nS, in which M is La(III)-Yb(III), L 3 is C 26 H 18 N 6 , X is a mononegative ion, and S is water or methanol, were obtained by metal-templated condensation from 2,6-diformylpyridine and 1,2-diaminobenzene, as well as by metal exchange from Ba(L 3 ) 2 (ClO 4 ) 2 . The spectral properties of the complexes (IR and 1 H and 13 C NMR spectra for the diamagnetic species) closely resembled those of the Sr(II) analogue, the structure of which was established by X-ray analysis

The reaction of diazo compounds with alkenes catalysed by complex [RuCl(cod)(Cp)] (cod = 1,5-cyclooctadiene, Cp = cyclopentadienyl) has been studied. The catalytic cycle involves in the first step the decomposition of the diazo derivative to afford the reactive [RuCl(Cp){=C(R(1))R(2)}] intermediate and a mechanism is proposed for this step based on a kinetic study of the simple coupling reaction of ethyl diazoacetate. The evolution of the Ru-carbene intermediate in the presence of alkenes depends on the nature of the substituents at both the diazo N(2)=C(R(1))R(2) (R(1), R(2) = Ph, H; Ph, CO(2)Me; Ph, Ph; C(R(1))R(2) = fluorene) and the olefin substrates R(3)(H)C=C(H)R(4) (R(3), R(4) = CO(2)Et, CO(2)Et; Ph, Ph; Ph, Me; Ph, H; Me, Br; Me, CN; Ph, CN; H, CN; CN, CN). A remarkable reactivity of the complex was recorded, especially towards unstable aryldiazo compounds and electron-poor olefins. The results obtained indicate that either cyclopropanation or metathesis products can be formed: the first products are favoured by the presence of a cyano substituent at the double bond and the second ones by a phenyl.

The preparation of the new ligand 8-(di-tert-butylphosphinooxy)quinoline (1) and the palladium derivatives [PdCl2(1)] (2), [Pd(η3-all)(1)]+ [all = C3H5 (3a), 1-PhC3H4 (3b) and 1,3-Ph2C3H3 (3c)] and [Pd(η2-ol)(1)] [ol = dimethyl fumarate (4a) and fumaronitrile (4b)] is reported. The cationic species 3a–3c have been isolated as BF 4 - salts. The complex 3a(BF4) is obtained either from the reaction of 1 with [Pd(μ-Cl)(η3-C3H5)]2 or from the reaction of ClP(CMe3)2 with [Pd(η3-C3H5)(8-oxyquinoline)], followed in both cases by chloride abstraction with NaBF4. In the complexes, the ligand 1 is P,N chelated to the central metal, as shown by the X-ray structural analysis of 3a(BF4). At 25 °C in solution, 3a(BF4) and 3b(BF4) undergo a fast η3−η1−η3 dynamic process which brings about a syn–anti exchange only for the allylic protons cis to phosphorus, while for 4a and 4b a slow rotation of the olefin around its bond axis to palladium takes place. The complexes 2 and 3a(BF4) are efficient catalyst precursors in the coupling of the phenylboronic acid with aryl bromides and chlorides.

PA, C18H14C12N20282, Mr=425.36, tri- clinic, P1 (after structure determination), a-- 11.232(2), b=10.465(2), c=8.386(2) A, a= 107-07 (3), fl = 83-63 (4), y = 98.90 (3) °, V= 928.7 (4)/~3, Z = 2, Dx = 1.521 g cm -3, ,~(Mo Ka) = 0.71069 A,/1, = 5.27 cm -~, F(000)= 436, room tem- perature. Final conventional R value is 0.033 (wR = 0.041) for 2716 diffractometer-measured intensities with I___ 3tr(l). The molecular structure is charac- terized by the different conformations of the two thiazolidine rings, one of which is an envelope, and by opposite chirality of the two asymmetric C atoms. In the crystal structure both the enantiomers 2S,2'R and 2R,2'S are present. PB, CI8HI4C12N20282, Mr = 425.36, orthorhombic, Pbcn, a=7.759(2), b= 19.625 (4), c = 12.504 (3) A, V= 1904.0 (6) A 3, Z = 4, Dx = 1.483 g cm -3, a(Mo Ka) = 0.71069 A, /1, = 5.14cm -I, F(000)= 872, room temperature. Final conventional R value is 0.049 (wR = 0.067) for 1334 diffractometer-measured intensities with I_> 3tr(l). Because the molecular structure has exact C2 sym- metry, the two phenyl rings are strictly parallel and the conformations (half chair) of the two thiazolidine rings are the same as well as the chirality of the two asymmetric C atoms. Nevertheless both enantiomers 2R,2"R and 2S,2"S are in the crystal.

The X-ray structural characterization of ethyl 5-cyano-1,6-dihydro-2-isopropyl-6-oxo-3-pyridine carboxylate is reported. Its solid state conformation has been compared with that of ethyl 2-methyl- and 2- tert -butyl-5-cyano-1,6-dihydro-6-oxo-3-pyridine carboxylate and with the results of a quantum chemical analysis at MNDO level in order to study the structure-activity relationship. Theoretical data indicate that the 2-substituent appears to be primarily responsible for the potencies and the different inotropic activities (positive or negative) of compounds 1–3 .

Azetidine reacts in tetrahydrofuran (thf) at room temperature or below with the co-ordinated RNC ligand in each of the neutral cis-[MCl2(PPh3)(CNR)][M = Pd or Pt; R = C6H4OMe-p or But) and cationic trans-[MCl(PPh3)2(CNC6H4OMe-p)]BF4(M = Pd or Pt) complexes to form the corresponding derivatives containing the acyclic diaminocarbene moiety M–C([graphic omitted]H2)NHR. Azetidine reacts also with the bis(isocyanide) complexes cis-[PdCl2(CNR)2](R = But or C6H4OMe-p) converting one (R = But) or two (R = C6H4OMe-p) isocyanide ligands into acyclic carbenes. The isocyanide complexes cis-[MCl2(PMe2Ph)(CNC6H4OMe-p)](M = Pd or Pt) react in thf with 2 equivalents of azetidine to afford the cationic acyclic diaminocarbene complexes [MCl(PMe2Ph)([graphic omitted]H){C([graphic omitted]H2)NHC6H4OMe-p}]Cl containing a metal-co-ordinated azetidine ligand. In contrast to the reactions of the three-membered heterocycle aziridine with isocyanide ligands which lead to five-membered cyclic carbenes, the corresponding reactions of azetidine give no evidence of six-membered diaminocarbenes. The carbene complexes have been characterized by their elemental analyses, i.r., 1H, and 31P n.m.r. spectra and in a few cases by their 13C n.m.r. and mass spectra. The structure of [PdCl(PMe2Ph)([graphic omitted]H){C([graphic omitted]H2)NHC6H4OMe-p}]Cl·CH2Cl2 was determined by X-ray diffraction: space group P21/n, a= 24.849(4), b= 10.174(2), c= 11.895(2)A, β= 91.85(3)°, R= 0.054 (R′= 0.059) for 3 734 observed reflections. The geometry around Pd is a distorted square with the diaminocarbene ligand trans to chloride. The Pd–C(sp2) distance is 1.990(6)A and the bond lengths within the carbenoid system indicate extensive electronic delocalization.

New substituted benzyl iminoether derivatives of the type cis - and trans -[PtCl 2 { E -N(H) C(OMe)CH 2 –C 6 H 4 – p –R} 2 ] (R = Me ( 1a , 2a ), OMe ( 3a , 4a ), F ( 5a , 6a )) have been synthesized and characterized by elemental analyses, FT-IR spectroscopy and NMR techniques. The iminoether ligands are in the E configuration, which is stable in solution and in the solid state, as confirmed by the 1 H NMR data. Complex trans -[PtCl 2 { E -N(H) C(OMe)CH 2 –C 6 H 4 – p –F} 2 ] ( 6a ) was also characterized by an X-ray diffraction study. Complexes 1a – 6a have been tested against a panel of human tumor cell lines in order to evaluate their cytotoxic activity. cis -Isomers were significant more potent than the corresponding trans -isomers against all tumor cell lines tested; moreover, complexes 1a and 5a showed IC 50 values from about 2-fold to 6-fold lower than those exhibited by cisplatin, used as reference platinum anticancer drug.

Reaction of [PdCl(η 3 -2-Me-allyl)(Ph 2 PPy)] ( 1 ) with AgBF 4 affords the new dinuclear cationic complex [Pd(η 3 -2-Me-allyl)(μ-Ph 2 PPy)] 2 (BF 4 ) 2 ( 2 ). The X-ray structural analysis of 2 shows that the 2-pyridyldiphenylphosphine ligands adopt a binucleating role through the P and N atoms bridging two independent palladium centres to form an eight-membered metallocyclic ring. One of the anti hydrogen atoms of the allyl moiety was located very close to a phenyl ring of Ph 2 PPy indicating the occurrence of a CH/π interaction. Addition of one equivalent of Ph 2 PPy to complex ( 2 ) affords the mononuclear cationic complex [Pd(η 3 -2-Me-allyl)(Ph 2 PPy) 2 ](BF 4 ) ( 3 ).

New benzyliminoether derivatives [PtCl2{N(H)dC(OMe)CH 2Ph}2] of cis(1a , 1b) and trans(2a , 2b) geometry were prepared and characterized by means of elemental analysis, multinuclear NMR and FT-IR techniques, and X-ray crystallography; this latter was carried out for 1b. The cytotoxic properties of these new platinum-(II) complexes were evaluated in terms of cell growth inhibition against a panel of different types of human cancer cell lines. cis-[PtCl2{E-N(H) dC(OMe)CH 2Ph}2](1a) was significantly more potent than cisplatin against all tumor cell lines tested, showing IC50 values from about 2- to 17-fold lower than the reference compound. Chemosensitivity tests performed on cisplatin-sensitive and -resistant cell lines have demonstrated that complex 1a is able to overcome cisplatin resistance. Analyzing the mechanism by which complex 1a led to cell death, we have found that it induced apoptosis in a dose-dependent manner, accompanied by the activation of caspase-3. The in vivo studies carried out using two transplantable tumor models (L1210 leukemia and Lewis lung carcinoma) showed that derivative1a induced a remarkable antitumor activity in both tumor models, as measured by prolonged survival and reduced tumor mass compared to control groups.

The new dihydridobis(3-nitro-1,2,4-triazolyl)borate ligand, [H2B(tzNO2)2]-, has been synthesized in dimethylacetamide solution, using 3-nitro-1,2,4-triazole and KBH4 through careful temperature control, and characterized as its potassium salt. The zinc(II) and cadmium(II) complexes, {M[H2B(tzNO2)2]Cl(H2O)2}, have been prepared by metathesis of [H2B(tzNO2)2]K with ZnCl2 and CdCl2, respectively. The complexes likely contain a metal core in which the ligand is coordinated to the metal ions in the K2-N,N' or K4-N,N',O,O' fashion. A single-crystal structural characterization is reported for the potassium dihydrobis(3-nitro-1,2,4-triazolyl)borate. The potassium salt is polymeric and shows several K...N and K...O interactions.

The chloro complexes [PtCl2(RSR′)2] (1–10) (RSR′ = MeSCH2C(O)OMe, 1; MeSCH2C(O)OEt, 2; MeSCH2C(O)Omenthyl(−), 3; MeSCH2CH2C(O)OMe, 4; , 5; EtSCH2C(O)Me, 6; MeSCH(Me)C(O)Me, 7; MeSPh, 8; MeS-o-C6H4Me, 9; and MeS-o-C6H4Et, 10) are obtained in high yield (63–90%) by reaction of [PtCl2(PhCN)2] with the proper thioether in 1/2 molar ratio, in anhydrous chloroform, at reflux under argon for ca. 10 h. The X-ray crystal structure of [PtCl2(MeS-o-C6H4Me)2] (9) shows an almost regular trans square planar geometry (triclinic, space group P 1 ¯ , a 6.806(1), b 7.789(2), c 10.085(3) A, α 101.80(2)°, β 69.55(2)°, γ 115.27(2)°, R(Fo) 0.023, R w ( F o 2 ) 0.065 ). The dichloro complexes react with silver acetate in a complex manner, which depends on the nature of the thioether, and only with RSR′ = MeSPh the simple diacetato complex [Pt(OAc)2(RSR′)2] is obtained as the major product.