两个手性Salen型过渡金属配合物的合成、波谱与结构

本文报道了2个手性Salen型过渡金属配合物[(N,N′-bis(3-t-butyl-5-methylsalicylidene)-1S,2S-cyclohexanediamine-N,N′,O,O′) nickel(Ⅱ)] (1)和[(N,N′-bis(3-t-butyl-5-methylsalicylidene)-1S,2S-cyclohexanediamine-N,N′,O,O′) copper(Ⅱ)] (2)的合成、波谱与结构表征。它们由(1S,2S)-环己烷-1,2-二胺和3-叔丁基-5-甲基-2-羟基苯甲醛发生席夫碱缩合反应制得的配体分别与Cu(Ⅱ)和Ni(Ⅱ)盐反应而得到。产品经过红外光谱、元素分析、电喷雾质谱、紫外和圆二色光谱等方法表征,并测定其晶体结构。结果表明配合物1和2中的中心金属离子Cu(Ⅱ)和Ni(Ⅱ)均为四配位平面正方形配位构型,而且在其晶体堆积中观察到一种通过芳环之间弱π-π相互作用形成的二聚结构。     

Quinoline-based tetradendate nitrogen ligands stabilize the bis(micro-oxo) dinuclear manganese(iii,iii) core

Quinoline-based, tetradentate nitrogen ligands, N,N'-bis(2-quinolylmethyl)-N,N'-dialkyl-1,2-ethanediamine (alkyl = methyl, bqdmen; ethyl, bqdeen; isopropyl, bqdpen), have been investigated as the supporting ligands for the formation of bis(micro-oxo) dinuclear manganese complexes. Bis(micro-oxo)Mn(2)(iii,iii) complexes and were obtained for bqdmen and bqdeen, respectively, as evidenced by X-ray crystallography, whereas bqdpen did not afford any manganese complexes due to its steric bulk. Complexes and exhibit highly positive Mn(2)(iii,iii)/Mn(2)(iii,iv) and Mn(2)(iii,iv)/Mn(2)(iv,iv) redox couples relative to the corresponding pyridine-ligated (micro-O)(2)Mn(2)(iii,iii) complexes.     

NMR spectroscopic and X-ray crystallographic study of methylcobalt(III) compounds with saturated amine ligands

The (13)C chemical shifts of methylcobalt(III) compounds with saturated amine ligands in cis positions to the methyl group and a monodentate ligand, L = CN(-), NH(3), NO(2)(-), N(3)(-), H(2)O, or OH(-), in the trans position are reported. The amine ligands used, 1,2-ethanediamine (en), 1,3-propanediamine (tn), N,N'-bis(2-aminoethyl)-1,3-propanediamine (2,3,2-tet), N,N'-bis(3-aminopropyl)-1,2-ethanediamine (3,2,3-tet), and 1,4,8,11-tetraazacyclotetradecane (cyclam), all exert an apparent cis influence on the (13)C resonance signal of the coordinated methyl group. In the trans-[Co(en)(2)(CH(3))(L)](n+) series the (15)N resonance frequency of the coordinated en has also been measured. The influence of L on the en (15)N chemical shifts is reverse the influence on the methyl (13)C chemical shifts except in the case of L = NO(2)(-), which affects a further deshielding of the amine nitrogen nucleus. The methyl (1)J(CH) coupling constants in the trans-[Co(en)(2)(CH(3))(L)](n+) series range from 128.09 Hz (L = CN(-)) to 134.11 Hz (L = H(2)O). The crystal structures of trans-[Co(en)(2)(CH(3))(ClZnCl(3))], trans-[Co(3,2,3-tet)(CH(3))(N(3))]ClO(4), trans,trans-[(CH(3))(en)(2)Co(CN)Co(en)(2)(CH(3))](PF(6))(3)(CH(3)CN), and cis-[Co(en)(2)(CH(3))(NH(3))]ZnCl(4) were determined from low-temperature X-ray diffraction data.     

Influence of the chelate effect on the electronic structure of one-electron oxidized group 10 metal(II)-(disalicylidene)diamine complexes

The neutral and one-electron oxidized group 10 metal, Ni(II), Pd(II) and Pt(II), six-membered chelate Salpn (Salpn = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,3-propanediamine) complexes have been investigated and compared to the five-membered chelate Salen (N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-ethanediamine) and Salcn (N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexane-(1R,2R)-diamine) complexes. Reaction of the Salpn complexes with 1 equivalent of AgSbF(6) affords the oxidized complexes which exist as ligand radical species in solution and in the solid state. The solid state structures of the oxidized complexes have been determined by X-ray crystal structure analysis. While the Ni and Pt analogues exhibit an essentially symmetric coordination sphere contraction upon oxidation, the oxidized Pd derivative exhibits an asymmetric metal binding environment demonstrating at least partial ligand radical localization. In comparison to the oxidized Salen and Salcn complexes, the propyl backbone of the Salpn complexes leads to a larger deviation from a planar geometry in the solid state. The electronic structure of the oxidized Salpn complexes was further probed by UV-vis-NIR measurements, electrochemistry, EPR spectroscopy, and theoretical calculations. The intense NIR band for the one-electron oxidized Salpn complexes shifts to lower energy in comparison to the 5-membered chelate analogues, which is attributed to lower metal d(xz) character in the β-LUMO for the Salpn series. The reactivity of the one-electron oxidized Salpn complexes with exogenous ligands was also studied. In the presence of pyridine, the oxidized Ni analogue exhibits a shift in the locus of oxidation to a Ni(III) species. The oxidized PtSalpn complex rapidly decomposes in the presence of pyridine, even at low temperature. Interestingly, electronic and EPR spectroscopy suggests that the addition of pyridine to the oxidized Pd analogue results in initial dissociation of the phenoxyl radical ligand, likely due to the increased flexibility of the propyl backbone.     

Synthesis, X-ray crystallographic, and NMR characterizations of platinum(II) and platinum(IV) pyrophosphato complexes

A series of mononuclear cis-diamineplatinum(II) pyrophosphato complexes containing ammine (am), trans-1,2-cyclohexanediamine (dach), and 1,2-ethanediamine (en) as the amine ligands were synthesized and characterized by (31)P and (195)Pt NMR spectroscopy. Chemical shifts of (31)P NMR resonances of these completely deprotonated complexes appear at 2.12, 1.78, and 1.93 ppm, indicating a coordination chemical shift of at least 8 ppm. The (195)Pt NMR chemical shifts for the am and dach complexes were observed at -1503 and -1729 ppm. The complexes are highly stable at neutral pH; no aquation due to the release of either phosphate or amine ligands was observed within 48 h. Furthermore, no partial deligation of the pyrophosphate ligand was detected within several days at neutral pH. At lower pH, however, release of a pyrophosphate ion was observed with concomitant formation of a bridged pyrophosphatoplatinum(II) dinuclear complex. The extended crystal structure containing the dach ligand revealed a zigzag chain stacked in a head-to-tail fashion. Moreover, two zigzag chains are juxtaposed in a parallel fashion and supported by additional hydrogen bonds reminiscent of DNA structures where two strands of DNA bases are held by hydrogen bonds. Theoretical calculations support the notion that the two dinuclear units are held together primarily by hydrogen bonds between the amine and phosphate moieties. Platinum(II) pyrophosphato complexes were readily oxidized by hydrogen peroxide to yield cis-diamine-trans-dihydroxopyrophosphatoplatinum(IV) complexes. Two of these complexes, containing am and en, were characterized by X-ray crystallography. Notable structural features include Pt-O (phosphate) bond distances of 2.021-2.086 A and departures from 180 degrees in trans-HO-Pt-OH bond angles, >90 degrees in O-Pt-O, and >90 degrees in cis-N-Pt-N bond angles. The departure in the trans-HO-Pt-OH angle is more pronounced in the 1,2-ethanediamine complex compared to the dach analogue because of the existence of two molecules possessing enantiomeric conformations within the asymmetric unit. (31)P NMR spectra exhibited well-resolved (195)Pt satellites with coupling constants of 15.4 Hz for the ammine and 25.9 Hz for both the 1,2-ethanediamine and trans-1,2-cyclohexanediamine complexes. The (195)Pt NMR spectrum of the ammine complex clearly showed coupling with two equivalent N atoms.     

Platinum(II) complexes with pi-conjugated, naphthyl-substituted, cyclometalated ligands (RC N N): structures and photo- and electroluminescence

The crystal structures and photophysical properties of mononuclear [(RC N N)PtX](ClO4)n ((RC N N)=3-(6'-(2'-naphthyl)-2'-pyridyl)isoquinolinyl and derivatives; X=Cl, n=0; X=PPh(3) or PCy(3), n=1), dinuclear [(RC N N)2Pt2(mu-dppm)](ClO4)2 (dppm=bis(diphenyphosphino)methyl) and trinuclear [(RC N N)3Pt3(mu-dpmp)](ClO4)3 (dpmp=bis(diphenylphosphinomethyl)phenylphosphine) complexes are presented. The crystal structures show extensive intra- and/or intermolecular pipi interactions; the two (RC N N) planes of [(RC N N)2Pt2(mu-dppm)](ClO4)2 (R=Ph, 3,5-tBu2Ph or 3,5-(CF3)2Ph) are in a nearly eclipsed configuration with torsion angles close to 0 degrees. [(RC N N)PtCl], [(RC N N)2Pt2(mu-dppm)](ClO4)2, and [(RC N N)3Pt3(mu-dpmp)](ClO4)3 are strongly emissive with quantum yields of up to 0.68 in CH2Cl2 or MeCN solution at room temperature. The [(RC N N)PtCl] complexes have a high thermal stability (T(d)=470-549 degrees C). High-performance light-emitting devices containing [(RC N N)PtCl] (R=H or 3,5-tBu2Ph) as a light-emitting material have been fabricated; they have a maximum luminance of 63,000 cd m(-2) and CIE 1931 coordinates at x=0.36, y=0.54.     

双[N,N'-亚烃基-2,2'-(芳亚甲基)二(3,4-二甲基吡咯-5-醛缩亚胺)]合双锰(Ⅱ)的合成、光谱特征及拟酶催化性能研究

首次报道了新型Schif碱类配体双[N,N-亚烃基-2,2-(苯亚甲基)二(3,4-二甲基吡咯-5-醛缩亚胺)]和双[N,N-(1,2-亚乙基)-2,2-(4-甲氧基苯亚甲基)二(3,4-二甲基吡咯-5-醛缩亚胺)]及其双锰配合物的合成方法、光谱特征及用配合物催化PhIO单加氧化环己烷反应的研究。     

Synthesis and Characterization of New Chiral Schiff Base Complexes with Diiminobinaphthyl or Diiminocyclohexyl Moieties as Potential Enantioselective Epoxidation Catalysts

New chiral Schiff base complexes have been obtained by condensation of 2,2'-diamino-1,1'-binaphthalene or 1,2-diaminocyclohexane and various salicylaldehydes and by subsequent metalation with manganese, iron, cobalt, nickel, copper, or zinc. The complete (1)H and (13)C NMR characterization of the ligands is reported, as are the X-ray crystal structures of (1R,2R)-(-)-N,N'-bis[3-(N,N-dimethylamino)salicylidene]-trans-1,2-cyclohexanediimine and [(1R,2R)-(-)-N,N'-bis(salicylidene)-trans-1,2-cyclohexanediiminato]copper(II). The new chiral manganese complexes have been evaluated in the oxygenation of prochiral olefins and sulfides using sodium hypochlorite, hydrogen peroxide, or N-methylmorpholine N-oxide/m-chloroperbenzoic acid as oxidant.     

新型Schiff碱双核配合物的合成及光谱特征

首次报道了新型Schiff碱双核配合物-双[N,N"-亚烃基-2,2'(苯亚甲基)二(3,4-二甲基吡咯-5醛缩亚胺)]合双锰及双铁配合物的合成方法及光谱特征。     

Synthesis and structural characterization of scandium SALEN complexes

A series of heteroleptic scandium SALEN complexes, [(SALEN)Sc(mu-Cl)]2 and (SALEN)Sc[N(SiHMe2)2] is obtained via amine elimination reactions using [Sc(N(i)Pr2)2(mu-Cl)(THF)]2 and Sc[N(SiHMe2)2]3(THF) as metal precursors, respectively. H(2)SALEN ligand precursors comprising H2Salen [(1,2-ethandiyl)bis(nitrilomethylidyne)bis(2,4-di-tert-butyl)phenol], H2Salpren [(2,2-dimethylpropanediyl)bis(nitrilomethylidyne)bis(2,4-di-tert-butyl)phenol], H2Salcyc [(1R,2R)-(-)-1,2-cyclohexanediyl)bis(nitrilomethylidyne)bis(2,4-di-tert-butyl)phenol] and H2Salphen [((1S,2S)-(-)-1,2-diphenylethandiyl)bis(nitrilomethylidyne)bis(2,4-di-tert-butyl)phenol] are selected according to solubility and ligand backbone variation ("=N-(R)-N=" bite angle) criteria. Consideration is given to the feasibility of [Cl --> NR2] and [N(SiHMe2)2--> OSiR3] secondary ligand exchange reactions. X-ray crystal structure analyses of donor-free (Salpren)Sc(N(i)Pr2), (R,R)-(Salcyc)Sc[N(SiHMe2)2], (Salen)Sc(OSi(t)BuPh2) and (Salphen)Sc(OSiH(t)Bu2) reveal (i) a very short Sc-N bond distance of 2.000(3) A, (ii) weak beta(Si-H)(amido)-Sc agostic interactions and (iii) an exclusive intramolecularly tetradentate and intrinsically bent coordination mode of the SALEN ligands with angle(Ph,Ph) dihedral angles and Sc-[N(2)O(2)] distances in the 124.27(9)-127.7(3) degrees and 0.638(1)-0.688(1) A range, respectively.     

Synthesis and characterization of complexes of UO2(II) and Th(IV) of bis-schiff bases derived from furoylpyrazolone

Four new complexes of UO₂(II) and Th(IV) with bis-Schiff bases, derived from N,N'-bis[(l-phenyl-3-methyl-5-oxo-4-pyrazolinyl)-a-furylmethylidyne]-1,2-propylenediimine [1,2-BPMOPFP-H₂] and N,N'- bis[(l-phenyl-3-methyl-5-oxo-4-pyrazolinyl)-a-furylmethylidyne]-1,3-propylenediimine [1,3-BPMOPFP-H₂], were synthesized and characterized by elemental analysis, IR, UV, ¹HNMR spectroscopy, and molar conductivity. The general formula of the complexes was confirmed to be [UO₂(BPMOPFP)], [Th(BPMOPFP)(NO₃)]NO₃. A possible structure for the complexes have been proposed.     

Copolymerization of cyclohexene oxide and carbon dioxide using (salen)Co(III) complexes: synthesis and characterization of syndiotactic poly(cyclohexene carbonate)

Synthetic routes to a series of new (salen-1)CoX (salen-1 = N,N'-bis(salicylidene)-1,2-diaminoalkane; X = halide or carboxylate) species are described and the X-ray crystal structures of two (salen-1)CoX (salen- = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane; X = Cl, I) complexes are presented. (R,R)-(salen-)CoX (X = Cl, Br, I, OAc, pentafluorobenzoate (OBzF(5))) catalysts are active for the copolymerization of cyclohexene oxide (CHO) and CO(2), yielding syndiotactic poly(cyclohexene carbonate) (PCHC), a previously unreported PCHC microstructure. Variation of the salen ligand and reaction conditions, as well as the inclusion of [PPN]Cl ([PPN]Cl = bis(triphenylphosphine)iminium chloride) cocatalysts, has dramatic effects on the polymerization rate and the resultant PCHC tacticity. Catalysts rac-(salen-)CoX (salen- = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminopropane; X = Br, OBzF(5)) have high activities for CHO/CO(2) copolymerization, yielding syndiotactic PCHCs with up to 81% r-centered tetrads. Using Bernoullian statistical methods, PCHC tetrad and triad sequences were assigned in the (13)C NMR spectra of these polymers in the carbonyl and methylene regions, respectively.     

Chiral helicity induced by hydrogen bonding and chirality of podand histidyl moieties

[structure: see text] The single-crystal X-ray structure determination of N,N'-bis[(S)-(+)-1-methoxycarbonyl-2-(4-imidazolyl)ethyl]-2,6-pyridinedicarboxamide (L-BHisPA) and the D-isomer (D-BHisPA) derived from the corresponding chiral histidine revealed a left- and right-handed helical conformation, respectively, through intramolecular hydrogen bonding and chirality of the podand histidyl moieties. Furthermore, each helical molecule is connected by continuous intermolecular hydrogen bonds to afford a left- or right-handed helical assembly, respectively, in the crystal packing.     

Pd, Pt, and Ru complexes of a pincer bis(amino)amide ligand

An improved synthesis of pincer ligand bis[(2-dimethylamino)phenyl]amine ((Me)N(2)NH) was reported. Reaction of the Li complex of (Me)N(2)N with suitable Pd, Pt, and Ru precursors gave the corresponding metal complexes. The structures of the Pd, Pt, and Ru complexes were determined. The Ru complex showed activity in catalytic transfer hydrogenation of aryl and alkyl ketones.     

Structures, photoluminescence, and reversible vapoluminescence properties of neutral platinum(II) complexes containing extended pi-conjugated cyclometalated ligands

Reacting K2PtCl4 with the tridentate R-C(wedge)N(wedge)C-H2 ligands 2,6-di-(2'-naphthyl)-4-R-pyridine (R = H, 1a; Ph, 1b; 4-BrC6H4, 1c; 3,5-F2C6H3, 1d) in glacial acetic acid, followed by heating in dimethyl sulfoxide (DMSO), gave complexes [(R-C(wedge)N(wedge)C)Pt(DMSO)] (2a-d). In the crystal structures of 2a-c, the molecules are paired in a head-to-tail orientation with Pt...Pt separations >6.3 A, and there are extensive close C-H...pi (d = 2.656-2.891 A), pi...pi (d = 3.322-3.399 A), and C-H...O=S (d = 2.265-2.643 A) contacts. [(Ph-C(wedge)N(wedge)C)Pt(PPh3)] (3) was prepared by reacting 2b with PPh3. Reactions of 2a-d with bis(diphenylphosphino)methane (dppm) gave [(R-C(wedge)N(wedge)C)2Pt2(mu-dppm)] (4a-d). Both head-to-head (syn) and head-to-tail (anti) conformations were found for 4a.6CHCl3.C5H12, whereas only one conformation was observed for 4b.2CHCl3 (syn), 4c.3CH2Cl2 (syn), and 4d.2CHCl3 (anti). In the crystal structures of 4a-d, there are close intramolecular Pt...Pt contacts of 3.272-3.441 A in the syn conformers, and long intramolecular Pt...Pt separations of 5.681-5.714 A in the anti conformers. There are weak C-H...X (d = 2.497-3.134 A) and X...X (X = Cl or Br; d = 2.973-3.655 A) interactions between molecules 4a-d and occluded CHCl3/CH2Cl2 molecules, and their solvent channels are of varying diameters (approximately 9-28 A). Complexes 2a-d, 3, and 4a-d are photoluminescent in the solid state, with emission maxima at 602-643 nm. Upon exposure to volatile organic compounds, 4a shows a fast and reversible vapoluminescent response, which is most intense with volatile halogenated solvents (except CCl4). Powder X-ray diffraction analysis of desolvated 4a revealed a more condensed molecular packing of syn and anti complexes than crystal 4a.6CHCl3.C5H12.     

希土高氯酸盐与N,N''—二(2—吡啶亚甲基)—1,2—乙二胺配合物的合成及性质研究

自六十年代以来,希土离子与芳香胺及其衍生物的配合物研究受到人们的普遍重视。     

Synthesis and crystal structure of uranium(IV) complexes with compartmental Schiff bases: from mononuclear species to tri- and tetranuclear clusters

Treatment of U(acac)4 with the hexadentate Schiff base H2L(i) gave the [UL(i)2] complexes 1-4 [H2L1=N,N'-bis(3-methoxysalicylidene)-2-methyl-1,2-propanediamine, H2L2=N,N'-bis(3-methoxysalicylidene)-1,2-phenylenediamine, H2L3=N,N'-bis(3-methoxysalicylidene)-2-aminobenzylamine and H2L4=N,N'-bis(3-methoxysalicylidene)-2,2-dimethyl-1,3-propanediamine for 1-4, respectively]. The [U(L(i))(acac)2] compounds could not be isolated because of their ready disproportionation into [UL(i)2] and U(acac)4. Compounds 2 and 4 adopt a meridional configuration in the solid state and in solution, while exists in solution as the two equilibrating meridional and sandwich isomers and crystallizes in the meridional isomeric form. Reaction of U(acac)4 with H4L5 afforded the expected compound [U(H2L5)(acac)2] (5) [H4L5=N,N'-bis(3-hydroxysalicylidene)-2-methyl-1,2-propanediamine] but, in the presence of H4L6 and H4L7, U(acac)4 was transformed in a serendipitous and reproducible manner into the tri- and tetranuclear U(IV) complexes [U3(L6)(HL6)2(acac)2] (6) and [U4(HL7)4(H2L7)2] (7) [H4L6=N,N'-bis(3-hydroxysalicylidene)-1,2-phenylenediamine and H4L7=N,N'-bis(3-hydroxysalicylidene)-2-aminobenzylamine]. The crystal structures of 6.3thf and 7.5thf show the assembling role of the Schiff-base ligands.     

Synthesis and structure of di(2-phenyl-8-quinolyl) diselenide and zinc bis[(2-phenyl-8-quinolyl)selenolate]

Di(2-phenyl-8-quinolyl) diselenide [2-(C₆H₅)C₉H₅NSe]₂ and zinc bis[(2-phenyl-9-quinolyl)selenolate], Zn [2-(C₆H₅)C₉H₅NSe]₂, have been synthesized. The molecular and crystal structure of the compounds were determined by X-ray structural analysis. The structures of the 2-phenyl-8-quinolylselenol ligand in the molecules of di(2-phenyl-8-quinolyl) diselenide and in the intracomplex compound of zinc are compared. The effect of the phenyl group in position 2 of the quinoline nucleus on the formation of the molecules and their packing in the crystal structure is discussed.     

Quinoxaline-benzimidazole rearrangement in the synthesis of benzimidazole-based podands

Alkylation of 3-benzoylquinoxalin-2(1H)-one with 1,5-dibromo-3-oxapentane, 1,8-dibromo-3,6-dioxaoctane, and α,ω-dihaloalkanes with different lengths of the polymethylene chain gave the corresponding quinoxaline podands. In the reaction with 1,2-dibromoethane, the N,O-rather than N,N′-alkylation product was obtained. The reaction of the obtained quinoxaline-based podands with benzene-1,2-diamine followed the quinoxaline-benzimidazole rearrangement pattern with formation of 2-(3-phenylquinoxalin-2-yl)benzimidazole-based podands.     

Anionic carbonato and oxalato cobalt(III) nitrogen mustard complexes

Synthetic approaches to cobalt(III) complexes [Co(L)(L')2] containing the bidentate dialkylating nitrogen mustard N,N-bis(2-chloroethyl)-1,2-ethanediamine (L = dce) together with anionic ancilliary ligands (L') which are either carbonato (CO3(2-)), oxalato (ox2-), bis(2-hydroxyethyl)dithiocarbamato (bhedtc-), 2-pyridine carboxylato (pico-) or 2-pyrazine carboxylato (pyzc-) were investigated. Synthetic routes were developed using the related amines N,N-diethyl-1,2-ethanediamine (dee) and 1,2-ethanediamine (en). The complexes [Co(CO3)2(L)]- (L = dee 1, dce 2), [Co(ox)2(L)]- (L = dee 3, dce 4), [Co(bhedtc)2(dee)]+ 5, [Co(bhedtc)2(en)]+ 6, mer-[Co(pico)3], mer-[Co(pyzc)]3 7 and [Co(pico)2(dee)]+ 8 were prepared and were characterised by IR, UV-Vis, 1H and 13C[1H] NMR spectroscopy, mass spectrometry and cyclic voltammetry. [Co(bhedtc)2(en)]BPh4 6b and trans(O)-[Co(pico)2(dee)]ClO4 8 were characterised by X-ray crystallography. In vitro biological tests were carried out on complexes 1-4 in order to assess the degree to which coordination of the mustard to cobalt attenuated its cytotoxicity, and the differential toxicity in air vs. nitrogen.