Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc（II） Complex with 2,2′-Diphenic Acid and 2,2′-Bipyridine Ligands

A new dinuclear complex [Zn(dpa)(bipy)(H2O)]2 (dpa = 2,2'-diphenic acid, bipy = 2,2'-bipyridine) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 10.960(2), b = 9.4841(18), c = 20.599(4), β = 104.452(3)o, V = 2073.4(7)3, C48H36N4O10Zn2, Mr = 959.55, Dc = 1.537 g/cm3, μ(MoKα) = 1.225 mm-1, F(000) = 984, Z = 2, the final R = 0.0364 and wR = 0.0843 for 2788 observed reflections (I > 2σ(I)). In the crystal structure, the zinc atom is five-coordinated with two carboxylate oxygen atoms from different dpas, one coordinated water molecule and two nitrogen atoms from bipy ligands, showing a slightly distorted triangular bipyramidal geometry. Furthermore, it exhibits a zero-dimensional network structure with a sixteen-membered ring and shows yellow photoluminescent property at room temperature.     

Solvothermal Synthesis and Crystal Structure of a Zn（II） Microporous Metal-organic Framework

A novel three-dimensional Zn(Ⅱ) coordination polymer, Zn3(C2H2N3)4(SiF6), has been synthesized under solvothermal conditions using 1H-1,2,4-triazole-3-carboxylic acid and zinc fluoride as the starting materials. The complex has been characterized by elemental analysis, IR, TG analysis and single-crystal X-ray diffraction analysis. The complex crystallizes in the tetragonal I4/mmm space group with a=11.592(0), c=7.526(1), V=1011.3(2)3 , Z=2, Mr=610.46, Dc=2.005 g/cm3 and F(000)=596. The final R=0.0312 and wR=0.067 for 319 observed reflections with I>2σ(I). In the title complex, the Zn centers are interconnected by μ 3 -bridging triazole ligands to form a microporous three-dimensional metal-organic framework.     

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.     

Hydrothermal Synthesis and Crystal Structure of a 2D Zinc（Ⅱ） Coordination Polymer with 5-Hydroxynicotinic Acid

The title compound,[Zn(5-hydroxynicotinate) 2 2H 2 O] n,has been synthesized by reacting zinc sulfate vitriol with 5-hydroxynicotinic acid under hydrothermal conditions,and its structure was determined by X-ray crystallography with the following data:monoclinic,space group C2/c,C 12 H 12 N 2 O 8 Zn,M r=377.61,a=10.223(3),b=10.319(3),c=13.613(4),β=105.922(6)°,Z=4,V=1380.9(8)3,F(000)=768,D c=1.816 g/cm 3,μ(MoKα)=1.826 mm-1,the final R=0.0401 and wR=0.1380 for 1157 observed reflections (I > 2σ(I)).In the structure of the title compound,the Zn II ion located in an inversion center lies in a distorted tetrahedral environment at a N 2 O 2 coordination mode,and the 5-hydroxynicotinic acid ligand links symmetry-related Zn II ions at a μ 2-N,O bridging way forming a two-dimensional covalent structure.In the crystal,solvent water molecules form intermolecular O-H O hydrogen bonds and pyridine rings of adjacent layers form π-π stacking (3.346),which connect adjacent two-dimensional sheets into a three-dimensional supramolecular network.     

A New 3D Supramolecular Network Formed by [Zn_3（2,6-Pyridinedicarboxylate）_3Cl_4]~（4-）and 4-Carboxypyridinium

A new compound [Zn3(C7NO4H3)3Cl4]·[C6NO2H6]4·4H2O (I) has been synthesized and structurally characterized by X-ray crystallography.It crystallizes in monoclinic,space group C2/c with a=16.9018(14),b=12.6902(10),c=25.1170(2),β=90.54°,V=5387.0(8)3,Z=4,Zn3C45H41Cl4N7O24,Mr=1401.76,Dc=1.728 g/cm3,F(000)=2840,μ(MoKa)=1.615 mm-1,the R= 0.0758 and wR=0.2060 for 3468 observed reflections (I 2σ(I)).Analysis of single-crystal X-ray diffraction data shows that compound I displays an interesting example of 3D supramolecular networks with perfect neutral and ionic hydrogen bonding array.     

Hydrothermal Syntheses and Crystal Structures of Zn(Ⅱ) and Co(Ⅱ) Complexes Constructed from 5-Methoxyisophthalic Acid and 1,10-Phenanthroline Ligands

Two new one-dimensional coordination polymers,[Zn(L)(phen)]n 1 and {[Co2(L)2(phen)2]·2H2O}n 2(H2L=5-methoxyisophthalic acid,phen=1,10-phenanthroline),have been obtained by hydrothermal conditions.According to their single-crystal X-ray diffraction analyses,complex 1 crystallizes in the monoclinic system,space group P2/c with a=8.9195(11),b=12.3620(15),c=17.0211(18),β=106.690(5)o,V=1797.7(4)3,the final R=0.0298 and wR=0.0715 for 3351 independent reflections with Rint=0.0353.Complex 2 crystallizes in the monoclinic system,space group C2/c with a=24.981(4),b=11.1204(19),c=18.125(3),β=132.5620(10)o,V=3708.5(11)3,the final R=0.0349 and wR=0.0914 for 3424 independent reflections with Rint=0.0214.Both 1 and 2 show L-bridged one-dimensional chain.1 and 2 are further assembled by π-π and hydrogen bonding interactions into 2-D layer structures,and they also display 3-D supramolecular frameworks through their other hydrogen bonds.Zn(Ⅱ) ion is five-coordinated with a distorted trigonal bipyramidal coordination geometry,while Co(Ⅱ) ion is six-coordinated and resides in a distorted octahedral coordination geometry.Additionally,complex 1 shows fluorescence in the solid state at room temperature.     

Hydrothermal Synthesis and Crystal Structure of a Znic(Ⅱ) Coordination Polymer Assembled by 4-Sulfophthalate and 4,4'-Bipyridine

A new organometallic coordinate polymer {[Zn2(4-sphth)2(4,4'-bpy)4(H2O)4][Zn(4,4'-bpy)2(H2O)4]}n·n[(4,4'-bpy)(H2O)4](4-sphth=4-sulfophthalic acid,4,4'-bpy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and characterized by elemental analysis,IR,fluorescence spectrum and single-crystal X-ray diffraction.The complex crystallizes in monoclinic,space group C2/c with a=18.8659(13),b=23.0861(13),c=22.5449(14),β=107.4120(10)o,V=9369.3(10)3,Mr=1981.86,Dc=1.405 g/cm3,μ(MoKα)=0.891 mm-1,F(000)=4100,Z=4,the final R=0.0644 and wR=0.1615 for 5984 observed reflections(I 2σ(I)).Furthermore,compound 1 shows blue photoluminescent property at room temperature.     

A New Two-dimensional Zinc Coordination Polymer Constructed by 1,3-Bis(4-pyridyl)-propane and Terephthalate: Synthesis and Crystal Structure

A new zinc coordination polymer, [Zn2(bpp)(tpa)2H2O] 1 (bpp=1,3-bis(4-pyridyl)-propane and tpa=terephthalate) has been hydrothermally synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. X-ray crystal structure analysis reveals that complex 1 crystallizes in monoclinic, space group P2/c with a=18.348(2), b=10.9080(14), c=13.7924(18), β=98.156(2)°, V=2732.5(6)3 , Z=4, C29H24N2O9Zn2 , Mr=675.24, Z=4, F(000)=1376, Dc=1.641 mg/m3 , μ=1.815 mm-1 , the final R=0.0443 and wR=0.0769 for 2715 observed reflections (I>2σ(I)). The title complex exhibits a two-dimensional (4, 4) sheet structure which is further stacked through face-to-face π-π interactions between the monodentately coordinated pyridine ring of bpp ligand and the phenyl ring of terephthalate ligand to form a 3-dimensional supramolecular structure. Thermogravimetric analyses show that the host framework of the complex is thermally stable up to ca. 400 ℃.     

Synthesis and Characterization of Nickel（Ⅱ） Complex Bearing 2,9- di-tert-butyl-1,10-phenanthroline Ligand

The complex DtbpNiCl2(Dtbp = 2,9-di-tert-butyl-1,10-phenanthroline) was synthe- sized and characterized by X-ray single-crystal structure analysis. For the complex: C20 H24 Cl2 N2 Ni CH2 Cl2, Mr = 506.95, monoclinic, space group P21 /c, a = 9.5905(3), b = 13.7587(3), c = 17.3364(5), β = 94.244(2)°, V = 2281.31(11)3, Z = 4, Dc = 1.476 g/cm3, λ = 1.54184, μ = 5.606 mm-1, F(000) = 1048, S = 1.079, R = 0.0402 and wR = 0.1010 for 3223 observed reflections with I 2σ(I). In complex DtbpNiCl2, the nickel adopts a distorted tetrahedral geometry coordinated by two nitrogen atoms of Dtbp and two chlorine ions. The complex is connected by intermolecular C–H···Cl hydrogen bonds to form a 1D structure in the solid state.     

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.     

Syntheses and Crystal Structures of Two Tin(Ⅳ) Complexes with Aminosilane Bearing Ligand

Aminosilane bearing bulky substituents on nitrogen: LH2(L=Me2Si(NDipp-)2 , Dipp=2,6-diisopropylphenyl) was reacted with BuLi in toluene. The resulting bulky chelating dianion Me2Si(NDipp-)2 was used to synthesize the unusual spirocyclic heterotriatomic complex [Me2Si(NDipp)2]2Sn (1) by its reaction with SnCl4 and the bulky heterotriatomic complex Me2Si(NDipp)2SnPh2 (2) with Ph2SnCl2.1 belongs to the monoclinic system, space group P21/n with a=13.193(2), b=20.663(3), c=20.403(3), β=99.954(2)o, V=5478.3(15)3 , C55H85.5N4Si2Sn, Mr=977.64, Z=4, Dc=1.185Mg/m3 , μ(MoKα)=0.547mm-1 , F(000)=2086, S=1.000, the final R=0.0614 and wR=0.1322 for 14446 observed reflections (I2σ(I)) and R=0.0797 and wR=0.1456 for all data. 2 belongs to the triclinic system, space group Pī with a=10.36(15), b=13.204(7), c=14.363(7), α=90.214(10), β=106.182(7), γ=109.854(8)o, V=1764.4(15)3 , C38H50N2SiSn, Mr=681.58, Z=2, Dc=1.283 Mg/m3 , μ(MoKα)=0.785 mm-1 , F(000)=712, S=1.002, the final R=0.0498 and wR=0.0955 for 7533 observed reflections (I2σ(I)) and R=0.0676 and wR=0.1018 for all data. In the structure of 1, the tin atom is located in the spirocyclic center of the two fused four-membered SnN 2 Si rings. The two complexes were characterized by 1H NMR, elemental analysis, and single-crystal X-ray structural analysis.     

Catena-dichloro(4,4′-dimethyl-2,2′-bipyridine)Cadmium(Ⅱ),a New One-dimensional Chain with Blue Fluorescent Emission

A new μ-chloro-bridged one-dimensional coordination polymer Cd(dmbpy)Cl2n(dmbpy=4,4′-dimethyl-2,2′-bipyridine) has been synthesized and structurally characterized by elemental analyses=IR=UV spectra and single-crystal X-ray diffraction.The complex crystallizes in the monoclinic system=space group C2/c with a=17.745(4)=b=10.326(2)=c=7.3382(15)=β=106.85(3)o=V=1286.9(4)3=Z=4=C12H12N2Cl2Cd=Mr=367.54=Dc=1.897 g/cm3=F(000)=720=λ(MoKα)=0.71073=μ=2.089 mm-1=R=0.0368 and wR=0.1048 for 1041 observed reflections(I > 2σ(I)).Cadmium(II) adopts a distorted octahedral coordination geometry and adjacent coordination chains are intercalated in a zipper-like fashion into 2D layers through the π-π stacking interactions between dmbpy.Fluorescent     

Supramolecular Formation via Hydrogen Bonding in Copper and Nickel Complexes with 2-Hydroxynicotinic Acid

Two complexes,Cu(HnicO)2 1 and Ni(HnicO)2(H2O)2 2 (H2nicO=2-hydroxy-nicolinic acid),were synthesized by hydrothermal reactions and structurally characterized. Complex 1 crystallizes in monoclinic,space group P21/n,with a=8.314(7),b=6.275(4),c=11.283(7),β =98.32(3)°,V=582.5(7)3,Z=2,Mr=339.74,Dc=1.937 g/cm3,F(000)=342,μ=1.908 mm-1,S =1.097,the final R=0.0284 and wR=0.0781 for 1177 observed reflections with I > 2σ(I). Complex 2 crystallizes in monoclinic,space group P21/c,with a=7.438(5),b=12.22(1),c=7.537(5),β=100.07(3)°,V=674.3(8)3,Z=2,Mr=370.95,Dc=1.827 g/cm3,F(000)=380,μ =1.487 mm-1,S=1.041,the final R=0.0335 and wR=0.0779 for 1202 observed reflections with I > 2σ(I). There are extended 3D framework structures in complexes 1 and 2 due to the N–H…O and C–H…O hydrogen bonds. The copper atom in 1 has square planar coordination,while the nickel atom in 2 adopts octahedral coordination geometry. The TG curve shows that complex 2 is stable in solid state to 150 ℃.     

Synthesis, Crystal Structure and Antibacterial Activity of a New Ternary Copper（Ⅱ） Complex with 2,6-Pyridinedicarboxylic Acid and 1,10-Phenanthroline

A new ternary copper(II) complex,[C 43 H 27 Cu 2 N 7 O 5 ]·[C 14 H 6 CuN 2 O 8 ]·6.5H 2 O,has been synthesized by the reaction of copper sulfate,2,6-pyridinedicarboxylic acid and 1,10-phenanthroline (phen),and characterized by elemental analysis,IR,UV and X-ray single-crystal diffraction.It crystallizes in triclinic,space group P1,with a=14.379(5),b=15.510(5),c=15.835(6),α=78.567(6),β=63.594(6),γ=81.287(6)°,V=3092.1(19)3,C 57 H 46 Cu 3 N 9 O 19.5,M r=1359.54,Z=2,D c=1.446 Mg/m 3,λ(MoKα)=0.71073,μ=1.101 mm-1,F(000)=1362,S=1.071,the final R=0.0718 and wR=0.11960 for 10705 observer reflections (I > 2σ(I)).The structure unit of the title complex consists of a mononuclear part and a di-nuclear part,and the three copper ions show three coordination modes.Each 6-coordinated geometry of the Cu atom is a distorted octahedral coordination geometry.The 3D supramolecular system is formed by the hydrogen bond O-H···O and π-π stacking interaction between neighboring single cells.The antibacterial activity of the title complex is also studied.     

Structure and Luminescent Property of a Novel 4-Hydroxyquinoline-2-carboxylate Based Zn（Ⅱ） Complex

A 3D coordination polymer [Zn2(hqc)2(H2O)]n has been obtained from the reaction of 4-hydroxyquinoline-2-carboxylic acid (H2hqc) with zinc(II) salt under hydrothermal condition, and characterized by elemental analysis, IR, TGA, PXRD and X-ray single-crystal diffraction. The complex crystallizes in the monoclinic system, space group P21/c with a = 14.305(2), b = 9.132(2), c = 15.356(2), β = 103.586(7)o, V = 1949.9(4)3, Z = 4, Dc = 1.782 g/cm3, μ = 2.508 mm-1, Mr = 523.06, F(000) = 1048, T = 293(2) K, λ(MoKα) = 0.71073, S = 1.008, the final R = 0.0329 and wR = 0.0745 for 3849 observed reflections (I > 2σ(I)). The title complex features a 3D framework via Zn(2) linking the 1D {Zn1(hqc)2}n chains. Thermogravimetric analysis shows that its framework is highly thermally stable up to 556 ℃ in the solid state.     

Synthesis and Crystal Structure of Tetra（（8-quinolyl）-amido-N）ytterbium Bi（tetrahydrofuran-O）lithium

The treatment of the mixture of n-BuLi with 1 equiv.8-aminoquinoline in THF in situ,which reacted further with 1/3 equiv.of YbCl3 in THF,to give the homoleptic lanthanide amide ate complex Yb(NH-C9H6N)4Li(C4H8O)2(1).The crystal structure was determined by X-ray diffraction and the following crystallographic data were obtained:C44H44N8O2YbLi,Mr = 896.85,monoclinic,space group C2/c,a = 7.8384(16),b = 22.294(5),c = 22.668(5),β = 97.614(5)°,V = 3926.3(14)3,Z = 4,Dc = 1.517 g/cm3,F(000)= 1812,μ(MoKα)= 2.431 mm-1,R = 0.0542 and wR = 0.1523 for 3372 observed reflections with I > 2σ(I).The structure of molecule 1 consists of one ytterbium atom,one lithium atom,four 8-aminoquinoline ligands and two THF molecules.The ytterbium atom is coordinated by eight nitrogen atoms of four 8-aminoquinoline ligands,forming a distorted dodecahedral geometry.     

Synthesis and Crystal Structure of Two Coordination Complexes Based on H2dpa and Tmd Ligands

Two new transition metal compounds, [Mn(dpa)2(tmd)2]n (1, H2dpa = 4-hydroxy-phenyl-acetic acid, tmd = 4,4-trimethylenedipyridine) and [Co4(dpa)6(tmd)4(H2O)4]n·nH2O·nCl2 (2), have been synthesized by hydrothermal synthesis. Compound 1 crystallizes in the monoclinic system, space group P21/n with a = 9.828(3), b = 17.493(5), c = 11.616(4), β = 110.146(6)o, V = 1874.9(10)3, C42H42MnN4O6, Mr = 753.74, Z = 2, Dc = 1.335 g/cm3, μ = 0.406 mm–1, F(000) = 790, the final R = 0.1047 and wR = 0.2021 for 2698 observed reflections (I > 2σ(I)). Compound 2 crystallizes in the monoclinic system, space group P21/c with a = 11.7214(13), b = 17.1582(19), c = 24.625(3), β = 103.055(3)o, V = 4824.4(9)3, C100H104Cl2Co4N8O23, Mr = 2094.55, Z = 2, Dc = 1.443 g/cm3, μ = 0.809 mm–1, F(000) = 2180, the final R = 0.0550 and wR = 0.0673 for 4104 observed reflections (I > 2σ(I)). These complexes were characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. The structural analyses show that the two compounds are both one-dimensional chain structures. However, compounds 1 and 2 form threedimensional supramolecular structures by hydrogen bonds, respectively.     

Synthesis and Crystal Structure of Bis{2-bromo- 4-chloro-6-[（2-isopropylammonioethylimino）- methyl]phenolato}bisthiocyanatozinc（Ⅱ）

A Schiff base zinc(Ⅱ) complex [Zn(C12H16BrClN2O)2(NCS)2] was prepared and characterized by elemental analysis,IR and single-crystal X-ray diffraction. The crystal belongs to the triclinic system,space group P1 with a=8.414(1),b=9.124(1),c=22.212(3),α=79.177(2),β=86.296(2),γ=89.899(2)o,V=1671.3(4)3,Z=2,Dc=1.631 g/cm3,Mr=820.79,λ(MoKα)= 0.71073,μ=3.444 mm-1,F(000)=824,R=0.0646 and wR=0.1179. A total of 7371 unique reflections were collected,of which 3904 with I > 2σ(I) were observed. The complex crystallizes with two half-molecules per asymmetric unit and each mononuclear molecule is centrosymmetric. The Zn atom lying at the inversion centre is six-coordinated in a slightly distorted octahedral geometry by two phenolate O atoms and two imine N atoms from two Schiff base ligands,as well as two N atoms from two thiocyanate anions. In the crystal structure,the combination of π-π stacking interactions and intermolecular hydrogen bonds (N–H…Br,N–H…O,N–H…N,C–H…O,C–H…S and C–H…Cl) leads to a three-dimensional network.     

Hydrothermal Synthesis,Structure and Photo-luminescence of a 2D Lead(Ⅱ) Coordination Polymer with (4,_6~3)Topology Based on Pb and 1,2,3,4-Butanetetracarboxylate Nodes

A lead(II) coordination polymer,{[Pb2(butca)(H2O)2](H2O)2}n (1),has been synthe-sized by the hydrothermal reaction of Pb(OH)2 and 1,2,3,4-butanetetracarboxylic acid (H4butca) at 160 °C.Single-crystal X-ray analyses reveal that it crystallizes in monoclinic,space group P21/c with a=7.616(5),b=7.584(4),c=12.314(7),β=105.595(12)o,V=685.0(7)3,Z=4,C8H14O12Pb2,Mr=716.57,Dc=3.474 g/cm3,μ=24.610 mm-1,F(000)=644,the final R=0.0381 and wR=0.1176 for 1465 observed reflections with I 2σ(I).The complex presents a 2D-layered structure featuring two different types of rings,and has a (4,36)topology based on Pb and butca4-nodes.In solid state,complex 1 shows photoluminescence with the maximum emission intensity at 468 nm under 286 nm excitation.     

Synthesis,Crystal Structure,DNA Binding and Catalytic Activities of a New Unsymmetrical Macrocyclic Dinuclear Zn(Ⅱ) Complex

An unsymmetrical macrocyclic dinuclear Zn(II) complex, [Zn2(H0.5L)(OAc)](ClO4)1.5(1, H2 L is the condensation product between 2, 6-diformyl-4-methylphenol and diethylenetriamine), was obtained and characterized by IR spectrum, elemental analysis and X-ray single-crystal diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 16.784(2), b = 19.474(3), c = 10.3364(13), β = 92.923(2)°, V = 3374.1(7) 3, Z = 4, Dc = 1.672 g/cm3, F(000) = 1740, μ = 1.651 mm-1, the R = 0.0609 and wR = 0.1696 for 4745 observed reflections(I 2σ(I)). The interactions of the complex with DNA have been measured by electrochemical studies, UV spectroscopy and viscosity experiment. The interactions of the complex with calf thymus DNA were studied by UV-vis spectra and the binding constant is 1.58 × 104 mol·L-1. The phosphate hydrolysis catalyzed by the complex was investigated using 4-nitrophenyl phosphate(NPP) as the substrate; the observed first order rate constant value is 3.0 × 10–4 s-1.