Complexes of cyclic aminomethylphosphines with Pt(II), Pd(II), Cu(I), and Ag(I) salts

1,3,5-Diazaphosphorinanes and 1,5,3,7-diazadiphosphacyclooctanes form complexes with Pt(II), Pd(II), Cu(I), and Ag(I) salts. Platinum and palladium are coordinated through phosphorous atoms. In the case of 1,3-diphenyl-5-p-toluidenomethyl-1,3,5-diazaphosphorinane complex formation with platinum and palladium is accompanied by formation of a new polydentate ligand, p-tolylbis-(1,3-di-p-tolyl-1,3,5-diazaphosphorinane-5-yl)methylamine, where the metal is also bonded to phosphorus atoms.DeceasedA. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 335–342, February, 1992.     

Directly linked dehydropurpurin-porphyrin dyads from Ag(I)-promoted oxidation of meso-phenylethynyl substituted zinc(II) porphyrins

Ag(I)-promoted oxidation of (5,15-diaryl-10-phenylethynyl-porphyrinato)zinc(II) complexes in CHCl3 gave directly linked 12,13-dehydropurpurin-porphyrin dyads, the structures of which were revealed by X-ray analysis.     

Hydrolytic metal-mediated coupling of dialkylcyanamides at a Pt(IV) center giving a new family of diimino ligands

Addition of excess R(2)NCN to an aqueous solution of K(2)[PtCl(4)] led to the precipitation of [PtCl(2)(NCNR(2))(2)] (R(2) = Me(2) 1; Et(2) 2; C(5)H(10) 3; C(4)H(8)O, 4) in a cis/trans isomeric ratio which depends on temperature. Pure isomers cis-1-3 and trans-1-3 were separated by column chromatography on SiO(2), while trans-4 was obtained by recrystallization. Complexes cis-1-3 isomerize to trans-1-3 on heating in the solid phase at 110 degrees C; trans-1 has been characterized by X-ray crystallography. Chlorination of the platinum(II) complexes cis-1-3 and trans-1-4 gives the appropriate platinum(IV) complexes [PtCl(4)(NCNR(2))(2)] (cis-5-7 and trans-5-8). The compound cis-6 was also obtained by treatment of [PtCl(4)(NCMe)(2)] with neat Et(2)NCN. The platinum(IV) complex trans-[PtCl(4)(NCNMe(2))(2)] (trans-5) in a mixture of undried Et(2)O and CH(2)Cl(2) undergoes facile hydrolysis to give trans-[PtCl(4)[(H)=C(NMe(2))OH](2)] (9; X-ray structure has been determined). The hydrolysis went to another direction with the cis-[PtCl(4)(NCNR(2))(2)] (cis-5-7) which were converted to the metallacycles [PtCl(4)[NH=C(NR(2))OC(NR(2))=NH]] (11-13) due to the unprecedented hydrolytic coupling of the two adjacent dialkylcyanamide ligands giving a novel (for both coordination and organic chemistry) diimino linkage. Compounds 11-13 and also 14 (R(2) = C(4)H(8)O) were alternatively obtained by the reaction between cis-[PtCl(4)(MeCN)(2)] and neat undried NCNR(2). The structures of complexes 11, 13, and 14 were determined by X-ray single-crystal diffraction. All the platinum compounds were additionally characterized by elemental analyses, FAB mass-spectrometry, and IR and (1)H and (13)C[(1)H] NMR spectroscopies.     

Pt(II) or Ag(I) salt catalyzed cycloisomerizations and tandem cycloadditions forming functionalized azacyclic arrays

[reaction: see text] Cyclic ene-N-p-toluenesulfonamides tethered to an electron-deficient alkyne undergo cycloisomerizations readily under the influence of catalytic Pt(II) salts (PtCl2 or [dppbPtmu-OH]2(BF4)2) or AgOTf. Yields for this process range from 47% to 99%. The resulting functionalized 2-azahydrindans can be reacted further using the Diels-Alder reaction. Tandem cycloisomerization-cycloaddition reactions in one pot generate highly functionalized 1-azadecalin ring systems in a highly stereocontrolled manner.     

Lumineszierende Cu(I)- und Ag(I)-Cluster mit Thionoliganden

Zusammenfassung Cu(I) bildet mit zahlreichen nicht lumineszierenden Thionoliganden (N-monosubstituierten N-Sulfonylthioharnstoffen, N,N-Dialkyl-N-phenylthioharnstoffen und N,N-Dialkylmonothiocarbamaten) rot lumineszierende oktaedrische Cluster (CuL)₆. Die Lumineszenz tritt sowohl im Festzustand als auch in Lösungen auf. Abklingzeiten von 10^–5s deuten auf kurzlebige Phosphoreszenz hin. Der Einfluß verschiedener Strukturelemente auf die Lage der Emissionsmaxima wird diskutiert. Dabei bewirken Veränderungen in der Metall-Ligand-Koordination die stärkste Verschiebung der Lumineszenzbanden. Tetraedrische (CuL)₄-Cluster mit den obigen Thionoliganden zeigen keine Lumineszenz. Generelle Unterschiede in der Struktur oktaedrischer und tetraedrischer Cluster werden diskutiert.Ag(I) bildet nur mit N-Alkyl-N-sulfonylthioharnstoffen lumineszierende Cluster (AgL)₆. Die Lumineszenz ist im Gegensatz zu den Cu-Clustern auf den Festzustand beschränkt.

---

Luminescent Cu(I) and Ag(I) clusters with thiono ligands

Summary Octahedrical (CuL)₆ clusters with several non luminescent thiono ligands (N-monosubstituted N-sulfonylthioureas, N,N-dialkyl-N-phenylthioureas and N,N-dialkylmonothiocarbamates) show red luminescence in the solid state and in solution. The luminescence lifetimes of 10^–5s are typical of short lived phosphorescence. The emission bands are affected by structural variation of the ligand. Changes of the coordination bonds cause the strongest shifts of the luminescence maxima. Tetrahedrical (CuL)₄ clusters with the same thiono ligands are not luminescent. General structural differences between octahedral and tetrahedral clusters are discussed.(AgL)₆ clusters are only luminescent in the solid state and if the ligand is a N-monosubstituted N-sulfonylthiourea

     

Cu(I)-promoted one-pot click-SNAr reaction of nitrobenzaldehydes

A series of 1,4-disubstituted 1,2,3-triazoles containing formyl was synthesized from a variety of readily available nitrobenzaldehydes and alkynes via a convenient one-pot, click-S_NAr reaction with moderate to excellent yields. The reactions were easily carried out in hexamethyl phosphoramide in the absence of a base at 60 °C.     

Synthesis of benzofuran-2-one derivatives by copper(I)-promoted coupling reactions of o-bromophenol with active methylene compounds

Treatment of o-bromophenoxide anion with sodium salts of active methylene compounds in the presence of copper(I) bromide in dioxane afforded benzofuran-2-one derivatives. The phenoxide group of o- and p-bromophenol activates the coupling reaction.     

Solvent Extraction of Ag(I) and Cu(II) with New Macrocyclic Schiff Bases

Two new macrocyclic Schiff bases (II) and (III) containing nitrogen ‐ oxygen donor atoms were synthesized by reaction between diethylene triamine or 2,2′‐(ethylenedioxy)bis(ethylamine) and the intermediate compound: 1,4‐bis(6‐methoxy‐2‐formylphenyl)‐1,4‐dioxabutane (I). Identification of these macrocyclic Schiff bases: 1,12, 15,18, 29,32 ‐ hexaaza ‐ [3,4;8,9;20,21;26,27‐tetra‐(6′‐methoxyphenyl)]‐5,8,22,25‐tetraoxa cyclo tetratriacosine‐1,11,18,28‐tetraene. (II) 1,12,21,32‐tetraaza‐[3,4;9,10;23,24;29, 30‐tetra‐(6′‐methoxyphenyl)]‐5,8,15,18,25,28,35,38‐octaoxa cyclo ‐ tetracontane‐1,11,21,31‐tetraene. (III) were determined by elemental analysis (LC‐MS), (IR) and (¹H and ¹³C‐NMR) spectroscopy. The liquid‐liquid extraction of metal picrates such as Ag⁺ and Cu²⁺ from aqueous phase to organic phase was carried out using these ligands. The effect of chloroform and dichloromethane as organic solvents over the metal picrate extractions were investigated at 25 ± 0.1 °C by using atomic absorption spectrometer.     

Chelating or bridging Pd(II) and Pt(II) metalloligands from the functional phosphine ligand N-(diphenylphosphino)-1,3,4-thiadiazol-2-amine. New heterometallic Pd(II)/Pt(II) and Pt(II)/Au(I) complexes

The reaction of two equivalents of the functional phosphine ligand N-(diphenylphosphino)-1,3,4-thiadiazol-2-amine Ph2PNHC=NNCHS (2) with [PdCl2(NCPh)2] in the presence of NEt3 gives the neutral, P,N-chelated complex cis-[Pd(Ph2PN=CNN=CHS)2] ([Pd(2-H)2], 3b), which is analogous to the Pt(II) analogue cis-[Pt (Ph2PN=CNN=CHS)2] ([Pt(2-H)2], 3a) reported previously. These complexes function as chelating metalloligands when further coordinated to a metal through each of the CH-N atoms. In the resulting complexes, each endo-cyclic N donor of the thiadiazole rings is bonded to a different metal centre. Thus, the heterodinuclear palladium/platinum complexes cis-[Pt(Ph2PN=CNN=CHS)2PdCl2]([Pt(2-H)2·PdCl2], 4a) and cis-[Pd(Ph2PN=CNN=CHS)2PtCl2]([Pd(2-H)2·PtCl2], 4b) were obtained by reaction with [PdCl2(NCPh)2] and [PtCl2(NCPh)2], respectively. In contrast, reaction of 3a with [AuCl(tht)] occurred instead at the P-bound N atom, and afforded the platinum/digold complex cis-[Pt{Ph2PN(AuCl)=CNN=CHS}2] ([Pt(2-H)2(AuCl)2], 5). For comparison, reaction of 4a with HBF4 yielded cis-[Pt(Ph2PNH=CNN=CHS)2PdCl2](BF4)2([H24a](BF4)2, 6), in which the chelated PdCl2 moiety is retained. Complexes 3b, 4a·CH2Cl2, 4b·0.5C7H8, 5·4CHCl3 and 6 have been structurally characterized by X-ray diffraction.     

Extremely long axial Cu-N bonds in chiral one-dimensional zigzag cyanide-bridged Cu(II)(-)Ni(II) and Cu(II)(-)Pt(II) bimetallic assemblies

Preparations, crystal structures, and spectral and magnetic properties of two new chiral one-dimensional cyano-bridged coordination polymers, [Cu(II)L2]M(II)(CN)].2H2O (M(II) = Ni(II) (1) and Pt(II) (2), L = trans-cyclohexane-(1R,2R)-diamine) have been presented. Complex 1 crystallizes in the monoclinic P2(1) space group with a = 9.864(4) A, b = 15.393(8) A, c = 7.995(4) A, beta = 110.32(3) degrees , V = 1138.4(10) A3, and Z = 2, while 2 crystallizes in the monoclinic P2(1) space group with a = 9.899(3) A, b = 15.541(4) A, c = 8.102(2) A, beta = 111.02(2) degrees , V = 1163.6(5) A3, and Z = 2. The unique zigzag cyano-bridged chains along the crystallographic b axis consist of alternate chiral [CuL(2)]2+ cations and square-planar [M(CN)4]2- anions. One side of the axial Cu-N(triple bond C) bond distances are 2.324(6) and 2.34(1) A with Cu-N[triple bond]C angles of 137.8(6) degrees and 138.2(9) degrees for 1 and 2, respectively. On the other hand, the opposite side of the axial Cu-N(triple bond C) bond distances are 3.120(8) and 3.09(1) A with significantly large bent Cu-N[triple bond]C angles of 97.9(5) degrees and 96.8(7) degrees for 1 and 2, respectively. The novel axial bonding features of extremely long semi-coordination Cu-N bonds are attributed to coexistence of pseudo-Jahn-Teller elongation and electrostatic interaction in the unique zigzag cyano-bridged chains. The characteristic bonding features with overlap between small 3d (Ni(II)) or large 5d (Pt(II)) and 3d (Cu(II)) orbitals results in larger shifts in XPS peaks of not only Cu2p(1/2) and Cu2p(3/2) but also Ni2p(1/2) and Ni2p(3/2) for 1 than those of 2, which is also consistent with weak antiferromagnetic interactions with Weiss constants of -5.31 and -5.94 K for 1 and 2, respectively. The d-d, pi-pi*, and CT bands in the electronic, CD, and MCD spectra for 1 and 2 in the solid state at room temperature are discussed from the viewpoint of magneto-optical properties.     

Determination of Fe(II), Cu(II) and Ag(I) by using silica gel loaded with 1,10-phenanthroline

The modified silica gel with 1,10-phenanthroline adsorbed was obtained. The adsorption from aqueous solutions onto loaded silica gel of Fe(II), Cu(II) and Ag(I) and their complexes was studied. The loaded silica gel was applied to Fe(II), Cu(II) and Ag(I) reflectance spectroscopy determinations in water (detection limits 0.08, 0.03 and 0.01 ppm respectively). Visual test scales for Fe, Cu and Ag ion determinations in water were worked out.     

Anodic stripping voltammetry with carbon paste electrodes for rapid Ag(I) and Cu(II) determinations

The simultaneous determination of silver(I) and copper(II) is realized for the routine analysis of trace levels of these elements by anodic stripping voltammetry (ASV) at the carbon paste electrode (CPE). The electrochemical response is studied in 14 different supporting electrolytes, ranging from acidic solutions (pH 0.1) to neutral and basic (pH 9.7) media, and the parameters governing electrodeposition and stripping steps are characterized for each medium by the use of pseudo-voltammograms. Comparison between different modes of matter transport mechanisms is also given. The dynamic range of the method is 0.05 to 150 mug 1(-1) Ag(I) in the majority of the media studied and can be extended to 400 mug l(-1) in selected media, with a general reproducibility in the +/- 2% range for five replicate measurements. The total analysis time lies between approximately 30 s and 10 min. Activation of the CPE surface has been studied, but this pretreatment is demonstrated to be unfavourable and is replaced by a simpler unique 'cleaning' procedure of dipping the CPE in diluted nitric acid.     

Nitrile-amidine coupling at Pt(IV) and Pt(II) centers. An easy entry to imidoylamidine complexes

Treatment of trans-[PtCl4(RCN)2] (R = Me, Et, Ph, NEt2) with 2 equiv of the amidine PhC(=NH)NHPh in a suspension of MeCN (R = Me), CHCl3 (R = Et, Ph), or in CHCl3 solution (R = NEt2) results in the formation of the imidoylamidine complexes trans-[PtCl4{NH=C(R)N=C(Ph)NHPh}2] (1-4) isolated in good yields (66-84%). The reaction of soluble complexes 3 and 4 with 2 equiv of Ph3P=CHCO2Me in CH2Cl2 (40 degrees C, 5 h) leads to dehydrochlorination resulting in a chelate ring closure to furnish the platinum(IV) chelates [PtCl2{NH=C(R)NC(Ph)=NPh}2] (R = Ph, 5; R = NEt2, 6), accordingly, and the phosphonium salt [Ph3PCH2CO2Me]Cl. Treatment of 5 with 3 equiv of Ph3P=CHCO2Me at 50 degrees C for 5 d resulted in only a 30% conversion to the corresponding Pt(II) complex [Pt{NH=C(NEt2)NC(Ph)=NPh}2] (15). The reduction can be achieved within several minutes, when Ph2PCH2CH2PPh2 in CDCl3 is used. When the platinum(II) complex trans-[PtCl2(RCN)2] is reacted with 2 equiv of the amidine, the imidoylamidinato complexes [PtCl(RCN){NH=C(R)NC(Ph)=NHPh}] (8-11) and [PhC(=NH)NHPh] x HCl (7) are formed. The reaction of trans-[PtCl2(RCN)2] with 4 equiv of the amidine under a prolonged reaction time or treatment of [PtCl(RCN){NH=C(R)NC(Ph)=NHPh}] (8-11) with 2 more equiv of the amidine yields the complex bearing two chelate rings [Pt{NH=C(R)NC(Ph)=NHPh}2] (12-15). The treatment of cis-[PtCl2(RCN)2] (R = Me, Et) with the amidine gives ca. 50-60% yield of [PtCl2{NH=C(R)NHC(Ph)=NHPh}] (16 and 17). All of the platinum compounds were characterized by elemental analyses; FAB mass spectrometry; IR spectroscopy; 1H, 13C{1H}, and 195Pt NMR spectroscopies, and four of them (4, 6, 8, and 15) were also characterized by X-ray crystallography. The coupling of the Pt-bound nitriles and the amidine is metal-mediated insofar as RCN and PhC(=NH)NHPh do not react in the absence of the metal centers in conditions more drastic than those of the observed reactions. The nitrile-amidine coupling reported in this work constitutes a route to the synthesis of imidoylamidine complexes, some of them exhibiting luminescent properties.     

Complexes of 1,3,5-triphenyl-1,3,5-diazaphosphorinane with Pt(II), Co(II), Ni(II), AND Cu(I) salts

1,3,5-Triphenyl-1,3,5-diazaphosphorinanes form 21 complexes with Pt(II), Co(II), Ni(II), and Cu(I).³¹P NMR spectroscopy indicated that Pt, Co, and Ni are coordinated at the phosphorus atoms, while Cu(I) is coordinated at the nitrogen atoms.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 209–211, January, 1991.     

Thermal Studies of New Cu(I) and Ag(I) Complexes with Bipyridine Isomers

The complexes of the general formula MLSCN (M=Cu(I), Ag(I), L=2,2′-bipyridine=2-bipy, 4,4′-bipyridine=4-bipy or 2,4′-bipyridine=2,4′bipy) have been prepared and their IR spectra examined. The nature of metal-ligand coordination is discussed. Thermal decomposition in air of these complexes occurred in several successive endothermic and exothermic processes and the residue was Cu₂O and Ag, respectively. This revised version was published online in August 2006 with corrections to the Cover Date.     

Trisoxazoline/Cu(II)-promoted Kinugasa reaction. Enantioselective synthesis of beta-lactams

The reactions of nitrones with terminal alkynes, catalyzed by chiral (i)Pr-trisoxazoline 2a/Cu(ClO4)2.6H2O under air atmosphere, afforded beta-lactams in moderate to good yields with up to 85% ee. The diastereoselectivity depends on the alkyne. Propiolate gives the trans-isomer as a major product, while the other alkynes afford cis-disubstituted lactams predominantly. Copper(II) salt proved to be an efficient catalyst precursor for the first time in the Kinugasa reaction, and this allowed the reaction to be performed under a practical and convenient condition. An appropriate base used in this reaction was essential to control both diastereoselectivity and enantioselectivity. Compared with primary and tertiary amines, secondary amines gave higher enantioselectivities. The reaction scope and limitation as well as the mechanism were also studied.     

Luminescent Cu(I) and Ag(I) coordination polymers: Fast phosphorescence or thermally activated delayed fluorescence

Three luminescent Cu (I) and Ag (I) coordination polymers based on donor-acceptor motif ligands are reported.Two Cu (I) coordination polymers both exhibit fast phosphorescence,which another Ag (I) coordination polymer present TADF photoluminescence emission at room temperature.     

Luminescent Cu(I) and Ag(I) coordination polymers: Fast phosphorescence or thermally activated delayed fluorescence

By applying two donor-acceptor motif molecules, 5,10-di(pyridin-4-yl)-5,10-dihydrophenazine (L1) and 10,10'-di(pyridin-3-yl)-10H,10'H-9,9'-spiroacridine (L2), as ligands and CuI/AgCF₃CO₂ as metal salt, we synthesized three coordination polymers, namely, {Cu₄(L1)₂I₄} (CP1), {Cu(L2)I·CHCl₃} (CP2) and {Ag(L2)CO₂CF₃·CHCl₃} (CP3). X-ray crystallographic analysis revealed that three coordination polymers all feature one-dimensional (1D) linear chains which are consisting of molecular boxlike units. In comparison with low photoluminescence quantum yield (PLQY) of two ligands, three coordination polymers, CP1, CP2 and CP3, present more intense photoluminescence with PLQY of 15%, 46% and 34% at room temperature respectively. The PL emission of CP1 and CP2 at room temperature could be attributed to the fast phosphorescence with lifetime both around 5 μs due to effective intersystem crossing (ISC). Whilst, it is worth noting that CP3 exhibit thermally activated delayed fluorescence (TADF) emission at room temperature.     

Cu(I) catalysed cyclopropanation with enantiopure scorpionate type ligands derived from (+)-camphor or (-)-menthone

One-pot syntheses of three new enantiopure heteroscorpionate ligands derived from (+)-camphor or (-)-menthone are described. The ligands are obtained by reacting pyrazoles derived from (+)-camphor or (-)-menthone with sodium hydride and thionyl chloride. Subsequent reactions with pyridine and various aldehydes afford the tripod ligands in multi-gram amounts. Especially the menthopyrazole based ligand 6 showed encouraging ee values up to 69% in the Cu(I) catalysed enantioselective cyclopropanation of styrene with ethyl diazoacetate.     

Cu(II)-catalyzed oscillatory chemical reactions

The role of copper ions in the copper-catalyzed chemical reactions is discussed. It is pointed out that copper ions can induce oscillatory behavior in many systems for the following reasons: (1) Copper cations can exist in three oxidation states (+1, +2 and +3); (2) Copper cations can form precipitates and stable complexes with a large number of reactants and intermediates; (3) Copper ions can participate in both oxidation and reduction processes, due to the surprisingly large range of redox potentials exhibited by the Cu²⁺/Cu⁺ and Cu³⁺/Cu²⁺ couples (known redox potentials span from 0.1 to 1.8 V, depending on the counter-ion or ligand present).