cis-Diaquabis（di-2-pyrimidinyl sulfide- K2N,N） Cobalt（II） Ditetrafluoridoborate： Lone Pair-aromatic and Anion-П Interactions in the Self-assembly of Coordination Complex

The title complex, [Co(DprS)2 (H2O)2]2(BF4)4 (DprS is di-2-pyrimidinyl sulfide), was obtained and characterized by elemental analysis, FT-IR and X-ray crystallography. The complex crystallizes in space group P21/c with a=11.742(1), b=22.439(2), c=20.538(2) , β=109.713(5)°, Z=4, V=5094.3(3)3 , Dc=1.692 g·cm-3 , μ=0.929 mm-1 , F(000)=2600, R=0.0756 and wR=0.1929. The asymmetric unit of the title complex is comprised of two isomeric cobalt(Ⅱ) centers (Co(1) and Co(2)) with a cis-[Co(DprS)2(H2O)2]2+ moiety. Each Co(Ⅱ) center exhibits a similar distorted N4O2-octahedral coordination geometry surrounded by a pair of DprS in a N,N’-chelate mode and two aqua ligands in a cis-relationship. Unconventional S···π(pyrimidinyl), N···π(pyrimidinyl), and anion(BF4-)···π(pyrimidinyl) are found to combine with the C H···F and O H···F interactions to stabilize a whole three-dimensional framework with the mononuclear units (Co(1) and Co(2)). The ligand conformation will be also discussed.     

Synthesis,Crystal Structure and Electrochemistry Properties of a Cobalt(Ⅱ) Complex Based on Asymmetry Schiff Base Ligand

A new cobalt(II) complex [Co(NO2-salen)2]·1.5H2O containing mono acetalization Schiff base ligand(NO2-salen = N-5-nitro-salicylideneamino ethanato) has been prepared through one-pot template condensation, and has been structurally characterized by elemental analysis, IR spectra and X-ray diffraction. It is formulated as C18H23CoN6O7.5, crystallizes in the hexagonal system, space group of R-3c with α = 25.895(18), b = 25.895(18), c = 35.075(6), γ = 120o, V = 20368(3) and Z = 36. The ligand of 5-nitrosalicylaldehyde-ethylene-diamine takes unusual mono asymmetry mode. The Co(II) ion exhibits a coordination number of six, and assumes a distorted octahedral geometry with a N2O4 donor set. The neutral monomeric units of [Co(NO2-salen)2]·1.5H2O are linked into a one-dimensional(1D) structure via the intermolecular hydrogen bonds and weak π-π stacking interactions. Cyclic-voltammetry measurement reveals the oxidation and reduction processes for the complex are irreversible in nature.     

Synthesis and Crystal Structure of an Unusual Dodecacoordinated Lanthanum Complex by Phenanthroline and Nitrate （phenH）_2[La（NO_3）_5（phen）]·CH_3OH

Lanthanum complex (phenH)2[La(NO3)5(phen)]·CH3OH (1, phen=phenanthroline) was synthesized and characterized by single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/c with a=20.3040(3), b=10.7091(1), c=19.0771(2), β=102.090(1)°, V=4056.07(8)3, Z=4, Dc=1.676 g/cm3, μ= 1.142 mm-1, F(000)=2056, the final R=0.0346 and wR=0.0793 for 9981 (Rint=0.0358) independent reflections. The mononuclear complex 1 consists of four parts: two phenH+ cations formed by the protonation of phen, one complex anion [La(NO3)5(phen)]2-, and one solvent methanol molecule. The complex anion contains one phen and five nitrate ligands which both chelate the center La(III) ion, adopting a distorted twelve-coordinated icosahedral geometry. The cations, anion and solvent molecule are linked together by hydrogen bonds. One of the protonated phenanthrolines (phenH+) acting as cation connects to the anion via N–H…O hydrogen bond directly, and the other one links to the anion through an intermediate solvent CH3OH via N–H…O and O–H…O hydrogen bonds. By the plentiful additional weak C–H…O intermolecular hydrogen bonds, the compound molecules construct a two-dimensional layer structure.     

Synthesis,Crystal Structure and Photoluminescence of [Gd(C_6NO_2H_5)_3-(H_2O)_2]_(2n)·(nH_5O_2)(nHgCl_5)(2nHgCl_4)·(2nH_2O)

A heterometallic 4f-5d inorganic-organic metal-isonicotinato hybrid Gd(C6NO2H5)3-(H2O)22n·(nH5O2)(nHgCl5)(2nHgCl4)·(2nH2O) 1 has been synthesized via hydrothermal reaction and structurally characterized.Complex 1 crystallizes in the space group C2/c of monoclinic system with four formula units in a cell:a=24.234(8)=b=20.816(7)=c=15.333(3)=β=128.091(8)°=V=6088(3)3=C36H47Cl13Gd2Hg3N6O20=Mr=2260.92=Dc=2.467 g/cm3=S=0.896=μ(MoKα)=10.331 mm-1=F(000)=4216=R=0.0344 and wR=0.0629.The crystal structure analysis reveals that the title complex is characteristic of a one-dimensional chain-like structure.Photoluminescent investigation reveals that the title complex displays a broad and intense emission in the green region.     

Synthesis and characterization of MH···HOR dihydrogen bonded ruthenium and osmium complexes(η~5-C_5H_4CH_2OH)MH(PPh_3)_2(M = Ru,Os)

Treatment of RuCl2(PPh3)3 with 6-dimethylaminopentafulvene in THF in the presence of water produced(η5-C5H4CHO) RuCl(PPh3)2, which was reduced by NaBH4 to give the Ru–H···HO dihydrogen bonded complex(η5-C5H4CH2OH) RuH(PPh3)2. The dihydrogen bonded complex(η5-C5H4CH2OH)RuH(PPh3)2 could also be synthesized by the reduction of complex(η5-C5H4CHO)RuH(PPh3)2, which was obtained by the reaction of RuHCl(PPh3)3 with 6-dimethylaminopentafulvene in the presence of water. The analogous dihydrogen bonded osmium complex(η5-C5H4CH2OH)OsH(PPh3)2 was similarly prepared. Single crystal structures and DFT calculations support the presence of intra-molecular H···H interaction, with separations of around 1.9 to 2.0 .     

Syntheses and Crystal Structures of Two Coordination Polymers Based on a Flexible Ligand N,N＇-Diacetic Acid Imidazolium

Two coordination compounds with a flexible ligand N,N?-diacetic acid imidazolium(HDAM),{[Co(trans-DAM)(bipy)(H2O)2](OH)·4H2O}n 1 and {[Cd(trans-DAM)(bipy)(H2O)](NO3)?2H2O}n 2(bipy = 4,4'-bipyridine),were prepared and characterized by single-crystal X-ray diffraction.Compound 1 crystallizes in monoclinic,space group P2/n with a = 7.589(6),b = 11.444(2),c = 12.894(3),β = 90.99(3)°,V = 1119.8(4)3,Z = 4,C8.5H14N2O5.5Co0.5,Mr = 261.68,Dc = 1.552 g/cm3,F(000) = 546,μ = 0.832 mm-1,the final R = 0.0657 and wR = 0.1958.Compound 2 crystallizes in the monoclinic C2 space group with a = 17.479(4),b = 11.689(2),c = 11.670(2),β = 117.13(3)°,V = 2121.9(7)3,Z = 4,C17H21N5O10Cd,Mr = 567.79,Dc = 1.777 g/cm3,F(000) = 1144,μ = 1.096 mm-1,the final R = 0.0233 and wR = 0.0638.In 1,the Co(II) ions are linked by μ2-trans-DAM-and bipy ligands to build a 2D(4,4) rectangular grid layer,exhibiting a 4-connected sql net.As for 2,μ3-trans-DAM-and bipy bridge Cd(II) ions form a 2D double-layer,consisting of a couple of(4,4) grid layers,which can be viewed as a(3,4)-connected network.In both compounds,the 2D structures are stabilized by hydrogen bonding interactions to give 3D supramolecular frameworks.Additionally,FT-IR spectroscopy,UV-Visible spectroscopy,and the fluorescent properties are discussed.     

Synthesis and Crystal Structure of Diaquabis{2,4-dibromo-6-[(2-ethylaminoethylimino)methyl]-phenolato}nickel(Ⅱ) Dinitrate Diacetonitrile

The title mononuclear Schiff base nickel(Ⅱ) complex [Ni(C11H14Br2N2O)2(H2O)2]· 2NO3·2C2H3N was prepared and characterized by elemental analysis,IR spectrum,and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system,space group P21/n with a=15.534(2),b=7.647(1),c=16.435(2),β=103.252(2)o,V=1900.3(4)3,Z=2,Dc=1.750 g/cm3,Mr=1000.99,λ(MoKα)=0.71073,μ=4.776 mm-1,F(000)=996,the final R=0.0368 and wR=0.0724. A total of 3988 unique reflections were collected,of which 2764 with I > 2σ(I) were observed. The complex consists of a mononuclear [Ni(C11H14Br2N2O)2(H2O)2]2+ cation,two nitrate anions and two acetonitrile molecules. The Ni atom,lying on the inversion centre,is six-coordinated by two Schiff bases and two water molecules to assume an octahedral coordination geometry. The molecules in the crystal are linked through intermolecular hydrogen bonds of N–H…O,N–H…Br,O–H…O,O–H…N and C–H…O to form layers.     

Synthesis and Crystal Structure of a 1-D Chain Zinc（Ⅱ） Coordinated Polymer with N-p-Tolysulfonyl-glutamine

A novel coordination polymer {[Zn(ts-gln)(bipy)]3H2O}n (ts-glnH2=N-p-toly-sulfonyl-glutamine,bipy=2,2-bipyridine) has been prepared and structurally characterized by X-ray diffraction method. It crystallizes in orthorhombic,space group P212121 with a=8.2622(5),b=16.6244(10),c=18.2807(10) ,V=2510.9(3) 3,C22H28N4O8SZn,Mr=573.91,Z=4,Dc= 1.518 g/cm3,μ(MoKa)=1.115 mm-1,F(000)=1192,the final R=0.0262 and wR=0.0662 for 5691 independent reflections with Rint=0.0240. The zinc(Ⅱ) atom is coordinated by N(3) and N(4) atoms of a bipy molecule,two carboxylate O(1) and O(2A) and amino N(1) atoms of ts-gln ligands,resulting in a square-pyramidal geometry. The title complex consists of an infinite zigzag chain of zinc(Ⅱ) ions linked by the carboxylate of N-p-tolysulfonyl-glutamine.     

Synthesis and Characterization of a New Ligand 2-（4, 5-Dihydro-2-thiazolyl）-6-methoxylbenzothiazole and Its Dinuclear Co（II） Complex

A new ligand 2-(4,5-dihydro-2-thiazolyl)-6-methoxyl benzothiazole and its new dinuclear Co(II) coordination complex [Co(C11H10N2OS2)Cl2]2·2CHCl3 (1) have been synthesized and characterized. Complex 1 was synthesized by the reaction of Co(II) salt with 2-(4,5-dihydro- 2-thiazolyl)-6-methoxyl benzothiazole under room-temperature evaporation condition and struc- turally characterized by single-crystal X-ray diffraction analysis and IR spectroscopy. The supramolecular network of complex 1 is stabilized by the presence of intermolecular interaction, such as C–H···Cl hydrogen bonding and π-π stacking. The complex crystallizes in triclinic, space group P1 with a = 8.3288(12), b = 10.5273(15), c = 10.822(2), α = 93.416(3), β = 90.864(3), γ = 94.890(3)o, V = 943.60(2)3, Z = 2, Dc = 1.758 g/cm3, F(000) = 498 and μ = 1.840 mm-1. The final complex [Co(C11H10N2OS2)Cl2]2·2CHCl3 is a diplex bridged dinuclear complex consisting of two Co(II) ions, two ligands, two bridging Cl- anions and two terminal Cl- anions.     

Synthesis and Crystal Structure of Salicylyl-4-phenyl Thiosemicarbazide Lead with a Two-dimensional Network

A two-dimensional lead complex, [Pb(C14N3O2H12S)(NO3)]n·nH2O, was prepared by the reaction of salicylyl-4-phenyl thiosemicarbazide and lead nitrate. The compound (C14H13N4O6PbS, Mr=572.53) crystallizes in the monoclinic space group P21/c with a=11.2984(2), b=15.6628(7), c=11.1118(2), β= 113.564(2)n, V=1802.43(10)3, Dc=2.110 g/cm3, Z=4, μ(MoKα)= 9.515 mm·1, F(000)=1084, the final R=0.0394 and wR=0.0701 for 2552 observed reflections with I > 2σ(I). The Pb(II) ion displays a distorted octahedron in which the hypothesized stereochemically active lone pair occupies the apex. The compound exhibits a two-dimensional network structure formed by the zigzag one-dimensional chains joined by two μ-O of two nitrate groups in overlapping. A large ring exists in the two-dimensional layers. The TGA of the title compound has been studied.     

Synthesis and Crystal Structure of a 1-D Chain Zinc(Ⅱ) Coordinated Polymer with N-p-Tolysulfonyl-glutamine

A novel coordination polymer {[Zn(ts-gln)(bipy)]3H2O}n (ts-glnH2=N-p-toly-sulfonyl-glutamine,bipy=2,2-bipyridine) has been prepared and structurally characterized by X-ray diffraction method. It crystallizes in orthorhombic,space group P212121 with a=8.2622(5),b=16.6244(10),c=18.2807(10) ,V=2510.9(3) 3,C22H28N4O8SZn,Mr=573.91,Z=4,Dc= 1.518 g/cm3,μ(MoKa)=1.115 mm-1,F(000)=1192,the final R=0.0262 and wR=0.0662 for 5691 independent reflections with Rint=0.0240. The zinc(Ⅱ) atom is coordinated by N(3) and N(4) atoms of a bipy molecule,two carboxylate O(1) and O(2A) and amino N(1) atoms of ts-gln ligands,resulting in a square-pyramidal geometry. The title complex consists of an infinite zigzag chain of zinc(Ⅱ) ions linked by the carboxylate of N-p-tolysulfonyl-glutamine.     

Synthesis, Crystal Structure and Properties of Complex VO（C10H9NO3） （C13H10NO2）

Complex VO(C10H9NO3)(C13H10NO2)(C10H9NO2-3=N-salicylidene-L-alaninate, C13H10NO-2=N-phenylbenzohydroxamate) was synthesized and characterized by means of elemental analysis, IR, UV, 1H NMR spectroscopies, cyclic voltammetry and single crystal X-ray diffraction. The complex crystallized in a monoclinic system with space group P21 and crystal cell parameters a=0.9720(1) nm, b=1.8274(2) nm, c=1.2542(1) nm, β=104.868(9)°, V=2.1532(4) nm3, Mr=470.34, Z=2. The two oxygen atoms and the one nitrogen atom of the tridentate Schiff base ligand and the one oxime oxygen atom of the hydroxamate ligand coordinate to the vanadium atom, forming an equatorial plane, the two axial positions are respectively occupied by the oxygen atom of the oxovanadium and the carbonyl oxygen atom of the hydroxamate and the vanadium atom exhibits a distorted octahedral VO(ONO)(OO) coordination sphere. The 1H NMR spectrum suggests that the two isomers, endo and exo in a molar ratio of 1/1.7, coexist in the solution of the title complex in CDCl3. There exists a quasi-reversible one-electron redox reaction corresponding to VⅤ/VⅥ couple in the three non-aqueous solvents, and the redox potential E1/2 of the title complex substantially shifts in the direction of the positive voltage increase in the order: CH2Cl2＜CH3CN＜DMF.     

Synthesis,Crystal Structure,and Photoluminescent and Semiconductive Properties of [La(C_6NO_2H_5)_3-(H_2O)_2]_(2n)·(nH_5O_2)(nHgCl_5)(2nHgCl_4)·(2nH_2O)

A new heterometallic 4f-5d inorganic-organic metal-isonicotinic acid complex [La(C6NO2H5)3(H2O)2]2n·(nH5O2)(nHgCl5)(2nHgCl4)·(2nH2O) 1 has been synthesized via hydro-thermal reaction and structurally characterized. Complex 1 crystallizes in the space group C2/c of monoclinic system with four formula units in a cell:a =24.140(7),b=20.884(7),c=15.462(2),β=127.46(1)°,V=6187(3)3,C36H47Cl13Hg3La2N6O20,Mr=2224.24,Dc=2.388 g/cm3,Z=4,T=293(2) K,μ(MoKα)=9.401 mm-1,F(000)=4160 and R/wR=0.0376/0.0636 for 4130 observed reflections (I > 2σ(I)) and 5617 unique reflections. Complex 1 is characteristic of a one-dimensional polycationic chain-like structure. Photoluminescent investigation reveals that the title complex displays interesting emissions in violet and orange regions. The luminescence spectra show stronger orange emission than violet emission. Optical absorption spectra of 1 reveal the presence of a wide optical bandgap of 3.41 eV.     

Synthesis and Crystal Structure of a Co(Ⅱ) Complex with Taurine-5-methyl-2-hydroxyisophthalaldehyde Schiff Bases [Co(C_(13)H_(16)N_2O_7S_2)(H_2O)_3]_2·H_2O

The title complex CoL(H2O)32·H2O(C26H46N4O21S4Co2),where L = taurine-5-methyl-2-hydroxyisophthalaldehydes,has been synthesized and characterized by IR and X-ray diffraction analysis.The crystal of the complex belongs to the triclinic system,space group P1,with a = 11.197(4),b = 13.309(5),c = 14.486(5),α = 78.827(13),β = 70.547(11),γ = 81.058(13)°,Mr = 996.77,S = 1.08,V = 1987.2(13)3,Z = 2,Dc = 1.666 g/cm3,F(000)= 1032,μ = 1.131 mm?1,R = 0.0633 and wR = 0.1293.According to the structural analysis,the Co(Ⅱ)ion adopts a slightly distorted six-coordinated octahedral geometry.One N atom of the Schiff base of each molecule was hydrogenated to form hydrogen bond with O atom.Two coterminous molecules packed in one crystal water molecule are linked by intermolecular hydrogen bonds,thus generating an infinite chain constructed by hydrogen bonds.     

Synthesis, Structure and Luminescent Properties of a New Terbium（Ⅲ） Complex with 5-Bromoisophthalic Acid

The self-assembly of 5-bromoisophthalic acid (H2BIPA) with Tb(NO3)3·6H2O under hydrothermal conditions gives rise to a 3D coordination polymer, [Tb2(BIPA)3(CH3CH2OH)]n (1), which was characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal is of monoclinic system, space group P21/c with a = 19.2591(17), b = 8.2537(7), c = 18.5663(17), β = 104.4720(10)°, V = 2857.6(4)3, C26H15Br3O13Tb2, Mr = 1092.95, Dc = 2.540 g/cm3, F(000) = 2040, μ = 9.173 mm-1 and Z = 4. The final R = 0.0324 and wR = 0.0767 for 5299 observed reflections (I > 2σ(I)). Complex 1 displays an unusual three-dimensional (4,6)-connected network with (48.66.8)2(44.62)2(42.84) topology, which is different from [Tb(HBDC)(BDC)(H2O)4]·3.3H2O (BDC = isophthalate) because the -Br substituent of isophthalate results in different electronic effect and steric hindrance to change the coordination modes of carboxylate groups in the assembly process. Moreover, luminescent properties of 1 have also been investigated in the solid state.     

Synthesis and Crystal Structure of[Cu（dppb）（NO_3）]_2（dppb=1,4-Bis（diphenylphosphino）butane）

The synthesis and molecular structure of a new dinuclear copper(Ⅰ) complex [Cu(dppb)(NO 3)] 2 are reported.The compound crystallizes in the monoclinic system,space group P2 1 /n with a=12.830(3),b=10.899(2),c=19.666 (4),β=104.69(3)°,V=2660.1(9)3,Z=4,D c=1.378 g/cm 3,F(000)=1144,the final R=0.0600 and wR=0.0668 for 2951 observed reflections with I > 2σ(Ⅰ).The complex contains a folded Cu 2 P 4 core structure,with two Cu(Ⅰ) atoms being bridged by a pair of dppb ligands to form a 14-membered Cu 2 P 4 C 8 zigzag ring.The ligand sphere of each metal center is completed by a nitrate anion in a chelating fashion.     

Synthesis and Crystal Structure of a New Iron Complex with Cyclic Water Hexamers [Fe(CDTA)(H_2O)]·[Fe(1,10-phen)_3]·10H_2O·2OH

The title complex [Fe(CDTA)(H2O)]·[Fe(1,10-phen)3]·10H2O·2OH (CDTA = transcyclohexane-1,2-diamine-N,N,N,N′-tetraacetate) has been prepared and characterized by single-crystal X-ray diffraction analysis. The crystal adopts space group P with a = 12.793(4), b = 14.104(5), c = 17.880(5), V = 2792.2(1)3, Dc = 1.459 g/cm3, C50H66Fe2N8O21, Mr = 1226.81, F(000) = 1284, μ = 0.604 mm-1, Z = 2, R = 0.1055 and wR = 0.2581 for 8675 observed reflections (I > 2σ(I)). X-ray crystallography analysis exhibits that the title compound consists of two crystallographically independent molecules [Fe(CDTA)(H2O)] and [Fe(1,10-phen)3], and they are connected through O-H···O hydrogen bonds and π···π stacking interactions forming a 3D supramolecular structure. Interestingly, there is a cyclic water hexamer with chair conformation in this complex.     

Synthesis and Crystal Structure of Bis（p—aminotoluene）—bis（dimethylglyoximato） Cobalt（Ⅲ） Perchlorate

The title compound (C22H32.5ClCoN6O8.25,Mr=607.42)crystallizes in the orthorhombic system,space group c222 1 with a=11.320(2),b=20.933(4),c=23.936(5)A,V=5672(2)A^3,Dc=1.423g/cm^3,Z=8,μ(MoKα）=0.754mm^-1,F(000)=2532,R=0.0512 and wR=0.1190,There are eight complex molecules [Co(C4H6N2O2)(C4H8N2O2)(C7H9N)2]ClO4.0.25H2O of C2 crystallographic symmetry in a unit cell,including two crystallographically independent molecules,in which different orientations of the MePhNH2 groups are found.Two MephNH2 groups are in trans position for molecule A,and cis for B.The central metal atom is in a distroted octahedral environment.The hydrogen bonds of O-H(oxime)…O and N-H(p-aminotoluene group)…O construct an one-dimensional chain along the c axis in the title compound.     

Synthesis and Crystal Structure of the Diiron Azadithiolate Complex [（μ-SCH_2）_2NPh]Fe_2（CO）5（Ph_2PCH_2PPh_2）

Reaction of [(μ-SCH2)2NPh]Fe2(CO)6 with Ph2PCH2PPh2 in the presence of Me3NO·2H2O gave the title complex [(μ-SCH2)2NPh]Fe2(CO)5(Ph2PCH2PPh2)(1)in 78% yield.The new complex 1 was characterized by elemental analysis,spectroscopy and X-ray crys-tallography.It crystallizes in triclinic,space group P1 with a = 10.832(2),b = 12.003(2),c = 15.579(3),V = 1785.6(6)3,Z = 2,C32H26Fe2NO5PS2,Mr = 819.40,Dc = 1.524 g/cm3,μ(MoKα)= 1.064 mm-1,F(000)= 840,T = 113(2)K,the final R = 0.0543 and wR = 0.1218 for 6203 observed reflections(I > 2σ(I)).The Ph2PCH2PPh2 ligand resides in an axial position of the square-pyramidal coordination sphere of the Fe atom and trans to the benzene ring in order to reduce the steric repulsion between Ph2PCH2PPh2 and the benzene ring.     

Synthesis, Crystal Structure and DNA Binding Studies of a Nickel（II） Complex with 2-Aminomethylbenzimidazole and Demethylcantharate

A new mixed-ligand nickel(Ⅱ) complex, [Ni(L)(DCA)(H2O)]·2H2O (L = C8H9N3, 2-aminomethyl-benzimidazole, DCA2- = 7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, demethylcantharate, C8H8O5), has been synthesized and characterized. The structure of the complex was determined by single-crystal X-ray diffraction. It is of monoclinic system, space group P21/c with a = 7.7211(7), b = 12.0799(12), c = 19.7867(19), β = 100.390(6)°, V = 1815.2(3) nm3, Dc = 1.625 g·cm-3, Ζ = 4, F(000) = 928, R = 0.0314 and wR = 0.0822. In addition, the interaction between the complex and DNA was studied by means of fluorescence spectra and viscosity. The results indicate that the complex binds to DNA by the mode of partial intercalation with the Stern-Volmer constants Ksv of 3.81 × 104 mol·L-1.