presentation
Transcription
presentation
Advances in Hard-Modelling of Chemical Processes Marcel Maeder Department of Chemistry University of Newcastle Australia What is Chemometrics? The art of extracting information from measurements Introduction Thermostatting Ionic Strength pH Application CO2 What are the options? Soft Firm (Statistical) Hard EFA, ALS etc Classification /PLS type Model fitting Based on restrictions Based on calibration set Based on chemical model Resolution of chromatogram Octane rating of petrol Reaction A→B→C 3.500 3.5 3.000 2.500 3 2.000 2.5 1.500 2 1.000 1.5 0.500 0.000 -0.500 0 1 20 40 60 80 100 120 0.5 0 400 420 440 460 480 500 520 540 560 580 600 k1 = 0.21 ±0.02 0 50 100 400 500 600 700 0 Introduction Thermostatting Ionic Strength pH 5 10 15 k 2 = 0.057 ±0.005 20 25 400 450 500 550 600 Application CO2 What are the options? Soft Firm (Statistical) Hard EFA, ALS etc PCR/PLS type Model fitting Literature (Chemometrics) intermediate large very small Literature (Chemistry) very small Introduction Thermostatting small Ionic Strength very large pH Application CO2 Why hard-modelling, why not soft-modelling? M F Delaney, Analytical Chemistry, 1984, 56, 261R - 277R “ The methods can be classified into two groups - those in which assumptions about the system are made (e.g., number or identity of components, line shapes) and those in which no assumptions are made, other than (perhaps) linear system behavior. In the former case you get back what you assumed, in the latter you get what you get. “ Introduction Thermostatting Ionic Strength pH Application CO2 Advantages of Hard-Modelling Analysis generally much more robust than model-free analyses 3.5 3 2.5 2 1.5 1 0.5 0 Numerical values for essential constants, they can be • tabled • compared with other values • interpreted • analysed • etc. Introduction Thermostatting 400 0 420 5 440 10 460 15 480 20 500 25 400 520 540 450 560 500 580 550 600 600 k1 = 0.21 ±0.02 k 2 = 0.057 ±0.005 Ionic Strength pH Application CO2 Hard-Modelling 1.2 k1 A k2 B C 1.2 1 1 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0 0 400 The model: 450 500 -0.2 [A] = -k1[A] 550 600 0 1000 2000 3000 4000 5000 -0.2 The parameters to be fitted: [B] = k1[A] - k 2 [B] [C] = k 2 [B] integration [A] = [A]0 e-k1t [B] = [A]0 Introduction k1 (e-k1t -e-k 2t ) k 2 -k1 Thermostatting • k1, k2 • molar absorptivities of all species at all wavelengths (e.g. 3 11=33) • total 35 parameters Difficult ? Ionic Strength pH Application CO2 Hard-Modelling k1 A B 1.2 1 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0 0 400 Introduction C 1.2 1 -0.2 k2 450 500 550 600 0 -0.2 Thermostatting 1000 2000 3000 4000 5000 Fitted, using solver in excel, • only 2 parameters, k1, k2 • molar absorptivities ‘eliminated’ Ionic Strength pH Application CO2 Advances in Hard-Modelling of Chemical Processes Introduction Thermostatting Ionic Strength pH Application CO2 Industry - Research Laboratory 50% reaction 1% reaction 50% support 99% support Introduction Thermostatting Ionic Strength pH Application CO2 What is left to be done in Hard-Modelling ? Temperature Control → thermostatting Ionic Strength Control → inert salts pH Control buffers Introduction Thermostatting → Ionic Strength pH Application CO2 Temperature Control Why do we thermostat ? useless answer : • to keep the temperature constant better answer : • to keep the rate constants constant real answer : • to keep the computations simple Introduction Thermostatting Ionic Strength pH Application CO2 Computations How difficult is it to accommodate temperature changes during a process? Introduction Thermostatting Ionic Strength pH Application CO2 Example: A k1 k2 B k3 C Differential equations: [A] =-k1[A] + k 2[B] [B] = k1[A] - k 2[B]- k 3 [B] [C] = k 3 [B] Matlab code as part of ODE solver: c_dot(1,1)=-k(1)*c(1)+k(2)*c(2); c_dot(2,1)= k(1)*c(1)-k(2)*c(2)-k(3)*c(2); c_dot(3,1)= k(3)*c(2); Introduction Thermostatting Ionic Strength pH % A_dot % B_dot % C_dot Application CO2 2 very short programs do the computations AeqBtoC.m c0=[1;0;0]; % initial conc of A, Cat, B and C k=[.2;.1;.01]; % rate constants k1 and k2 times=[0:1:300]'; [times,C] = ode45('ode_AeqBtoC',times,c0,[],k); figure(1); plot(times,C) % call ode-solver % plotting C vs t xlabel('time');ylabel('conc.'); ode_AeqBtoC.m function c_dot=ode_AeqBtoC(t,c,flag,k) % A <-> B -> C Introduction c_dot(1,1)=-k(1)*c(1)+k(2)*c(2); % A_dot c_dot(2,1)= k(1)*c(1)-k(2)*c(2)-k(3)*c(2); % B_dot c_dot(3,1)= k(3)*c(2); % C_dot Thermostatting Ionic Strength pH Application CO2 1 A 0.9 0.8 k1 k2 B k3 C 0.7 conc. 0.6 0.5 0.4 0.3 0.2 0.1 0 Introduction 0 50 Thermostatting 100 150 time Ionic Strength 200 250 pH 300 Application CO2 How to accommodate temperature changes? Introduction Thermostatting Ionic Strength pH Application CO2 Arrhenius equation Arrhenius equation describes rate constant k as a function of the temperature (Eyring equation could be used as well) - Ea k = Ae RT A = pre-exponential factor Ea = activation energy R = gas constant ( = 8.314 J K-1 mol-1 ) T = temperature in K Introduction Thermostatting Ionic Strength pH Application CO2 Example: A k1 k2 k3 B [A] k1[A ] k2[B ] [B ] k1[A ] k2[B ] [C ] k3 [B ] k3[B ] [A] k1(T) [A ] k2 (T) [B ] [B ] k1(T) [A ] k2 (T) [B ] [C ] k3 (T) [B ] Introduction Thermostatting Ionic Strength C k3 (T) [B ] pH Application CO2 • • • The parameters are the Arrhenius parameters, A, Ea, not the rate constants The rate constants are computed using the Arrhenius parameters and the temperature The temperature has to be interpolated from the measured temperatures ode_AeqBtoC_T.m function c_dot=ode_AeqBtoC_T(t,c,flag,k,temp,A,Ea,times) % A <-> B -> C R=8.314; % gas constant J K-1 mol-1 T=lolipop(times,temp,t,2,5); % interpolation to comp T at particular time t k=A.*exp(-Ea./(R*(T+273))); % rate constants at T c_dot(1,1)=-k(1)*c(1)+k(2)*c(2); % A_dot c_dot(2,1)= k(1)*c(1)-k(2)*c(2)-k(3)*c(2); % B_dot c_dot(3,1)= k(3)*c(2); % C_dot Introduction Thermostatting Ionic Strength pH Application CO2 A side issue, lolipop.m lolipop.m function y1=lolipop(x,y,x1,nd,npoints) % % % % General Polynomial Inter/Extrapolation, degree nd, using npoints x,y,x1,y1 vectors - x,y do not have to be the same length as x1,y1 nd: degree of polynomials npoints: number of total points to define each polynomial for i=1:length(x1) N=sortrows([x y abs(x-x1(i))],3); % sort x,y by abs(x-x1(i)) x_npoints=N(1:npoints,1); y_npoints=N(1:npoints,2); % npoints nearest nodes a=polyfit(x_npoints-mean(x_npoints),y_npoints,nd); % polyn. par. y1(i)=polyval(a,x1(i)-mean(x_npoints)); % interpolate end Introduction Thermostatting Ionic Strength pH Application CO2 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 conc. conc. 1 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0 50 100 150 time 200 250 300 0 0 at 20 C 50 100 150 time 200 250 300 at 20-80 C Compression of process, similar to temperature program in GC or non-isocratic mobile phase in HPLC Introduction Thermostatting Ionic Strength pH Application CO2 Cyanoacetic acid + ethanol in equilibrium with the ester Introduction Thermostatting Ionic Strength pH Application CO2 Activity coefficients Why do we add inert salts ? useless answer : • to keep the ionic strength constant better answer : • to keep the rate constants constant real answer : • to keep the computations simple Introduction Thermostatting Ionic Strenght pH Application CO2 Example: [A] A B [B ] [C ] [A] k1[A ][B ] k1[A ][B ] [B ] [C ] k1 k2 C k 2[C ] k2[C ] -k1 { A }{ B } k 2 {C } k1 { A }{ B } - k2 {C } {A} = activity of species A Introduction Thermostatting Ionic Strenght pH Application CO2 Activity coefficients { A} A [ A] For Ionic compounds, activity coefficients can be approximated in reasonably dilute solutions as (Debye-Hückel): log A z2 1 With A parameter depending on dielectric constant of solvent, in water A~0.51 zi charge of species 1 [Ci ]zi2 Ionic strength of solution, computed as: 2 Introduction Thermostatting Ionic Strenght i pH Application CO2 function c_dot=ode_AplusBeqC_I(t,c,flag,k,c_I,charges,mode,A) % A + B <--> C mu log_gamma gamma act = = = = including activities sum(1/2*([c;c_I].*(charges.^2))); (-A*(charges.^2)*(mu^0.5))/(1+(mu^0.5)); 10.^log_gamma; c.*gamma(1:length(c)); c_dot(1,1)= -k(1)*act(1)*act(2)+k(2)*act(3) c_dot(2,1)= c_dot(1,1); c_dot(3,1)= -c_dot(1,1); Introduction Thermostatting % % % % ionic strength log gamma gamma activities % A_dot % B_dot % C_dot Ionic Strength pH Application CO2 Ni 2+ + ox d[Ni 2+ ] = dt = 2- k+ k- 0+ Ni(ox) k + × {Ni 2+ }{ox 2- } + k - × {Ni(ox)} k + × γNi2+ [Ni 2+ ] × γox 2- [ox 2- ] + k - × [Ni(ox)] γNi2+ , γox 2continuously change as the ionc strength decreases during the reaction γNi(ox) is 1, no charge Introduction Thermostatting Ionic Strength pH Application CO2 k+ as a function of ionic strength 5.5 d[Ni2+ ] = k+ × {Ni2+ }{ox 2- } + k- × {Ni(ox)} dt log k(+) 5 4.5 4 3.5 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 d[Ni2+ ] = k+ × [Ni2+ ][ox 2- ] + k- × [Ni(ox)] dt sqrt(IS) k- is not -dependent, as Ni(ox) has no charge Introduction Thermostatting Ionic Strength pH Application CO2 pH control Why do we add buffers ? useless answer : • to keep the pH constant better answer : • to keep the rate constants constant real answer : • to keep the computations simple Introduction Thermostatting Ionic Strength pH Application CO2 No Matlab files today, they are too complex to be discussed here. Introduction Thermostatting Ionic Strength pH Application CO2 Application: saving the planet by absorbing CO2 from power plants, post combustion capture PCC Introduction Thermostatting Ionic Strength pH Application CO2 The Scale of the Problem The mass of CO2 produced by human activities (~25Gt/y as CO2; ~7Gt/y carbon) is about the same as the mass of everything else produced by humans (including waste) put together. Introduction Thermostatting Ionic Strength pH Application CO2 CO2 output of power station 11.8 106 t/y 33000 t/d = 4.4 106 m3/d 100m CO2 / day 100m 100m + N2 Introduction Thermostatting Ionic Strength pH Application CO2 The Principle of PCC CO2 N2 CO2 N2 time heat base, e.g. NaOH Na2CO3 NaOH or better R-NH2 RNH3+, HCO3- R-NH2 Introduction Thermostatting Ionic Strength pH Application CO2 schematic diagram of PCC plant N2 CO2-free gas CO2 high temp stripper (100-140 C) low temp absorber (40-60 C) CO2 lean solution flue gas CO2 N2 CO2 rich solution Introduction Thermostatting Ionic Strength pH Application CO2 First questions a chemist is asking: • What are the molecules that interact in PCC ? • How do they interact with each other ? Introduction Thermostatting Ionic Strength pH Application CO2 What are the molecules that interact in PCC ? {CO2} amine, {RNH2} CO2(aq), H2CO3 HCO3-, CO32- RNH2, RNH3+ carbamate, {RNHCO2-} RNHCO2-, RNHCO2H Introduction Thermostatting Ionic Strength pH Application CO2 How is the carbamate formed? {CO2} CO2(aq), H2CO3 HCO3-, CO32- + amine, {RNH2} carbamate, {RNHCO2-} RNH2, RNH3+ RNHCO2- , RNHCO2H 1 molecule CO2 (aq) H2CO3 HCO-3 CO2- + + 1 molecule RNH2 RNH+ 3 1 molecule RNHCO-2 RNHCO2H 3 Introduction Thermostatting Ionic Strength pH Application CO2 pH K4 H2CO3 k-1 k7 k-2 k1 k8 k-7 CO2 +H2O k9 K3 HCO-3 k2 k-8 H2O - KW/K6 CO2 (aq)+OH k-9 RNHCO2H K10 RNH2 RNHCO-2 RNH+3 Introduction Thermostatting CO23 Ionic Strength K5 RNH2 pH Application CO2 pH K4 H2CO3 k-1 k7 k1 k-2 k8 k-7 CO2 +H2O k9 K3 HCO-3 H2O k2 k-8 KW/K6 CO2 +OH- k-9 RNHCO2H K10 RNH2 RNHCO-2 RNH+3 Introduction Thermostatting CO23 Ionic Strength K5 RNH2 pH Application CO2 pH K4 H2CO3 k-1 k7 k1 k-2 k8 k-7 CO2 +H2O k9 K3 HCO-3 H2O k2 k-8 KW/K6 CO2 +OH- k-9 RNHCO2H K10 RNH2 RNHCO-2 RNH+3 Introduction Thermostatting CO23 Ionic Strength K5 RNH2 pH Application CO2 pH K4 H2CO3 k-1 k7 k1 k-2 k8 k-7 CO2 +H2O k9 K3 HCO-3 H2O k2 k-8 KW/K6 CO2 +OH- k-9 K10 Introduction RNH2 RNHCO-2 RNHCO2H Thermostatting CO23 RNH+3 Ionic Strength K5 RNH2 pH Application CO2 pH K4 H2CO3 k-1 k7 k1 k-2 k8 k-7 CO2 +H2O k9 K3 HCO-3 H2O k2 k-8 KW/K6 CO2 +OH- k-9 K10 Introduction RNH2 RNHCO-2 RNHCO2H Thermostatting CO23 RNH+3 Ionic Strength K5 RNH2 pH Application CO2 pH K4 H2CO3 k-1 k7 k1 k-2 k8 k-7 CO2 +H2O k9 K3 HCO-3 H2O k2 k-8 KW/K6 CO2 +OH- k-9 K10 Introduction RNH2 RNHCO-2 RNHCO2H Thermostatting CO23 RNH+3 Ionic Strength K5 RNH2 pH Application CO2 pH K4 H2CO3 k-1 k7 k1 k-2 k8 k-7 CO2 +H2O k9 K3 HCO-3 H2O k2 k-8 KW/K6 CO2 +OH- k-9 K10 Introduction RNH2 RNHCO-2 RNHCO2H Thermostatting CO23 RNH+3 Ionic Strength K5 RNH2 pH Application CO2 The complete reaction scheme CO (aq) + RNH RNHCO H H CO + RNH RNHCO H 2 2 3 2 2 2 2 HCO + RNH 3 RNHCO RNHCO 2 2 + 2 H+ RNHCO H 2 + CO2(aq) + H2O H2CO3 CO2(aq) + OH- HCO3 CO23 H+ HCO3 HCO3 + H+ H2CO3 RNH2 + H+ RNH3 + Reactions involving carbamates Other, known reactions To be determined: • 6 rate constants • 1 equilibrium constants • - 3 due to microscopic reversibility Introduction Thermostatting Ionic Strength pH Application CO2 Measurement techniques • • • • • p(CO2) partial pressure in gas phase (slow) Ba(CO3) precipitation (slow) Conductometry (fast, not specific) pH, indicator (fast) NMR – 13C-NMR (slow, not quantitative) – 1H-NMR (intermediate, quantitative) Introduction Thermostatting Ionic Strength pH Application CO2 Side issue: translation of model into Matlab code A k1 k3 B k2 c_dot(1,1)=-k(1)*c(1)+k(2)*c(2); c_dot(2,1)= k(1)*c(1)-k(2)*c(2)-k(3)*c(2); c_dot(3,1)= k(3)*c(2); C % A_dot % B_dot % C_dot pH K4 H2CO3 k-1 HCO-3 k1 k7 K3 k-2 CO23 H2O k2 ? k8 k-7 k-8 CO2 +H2O k9 KW/K6 CO2 +OH- k-9 RNH2 RNHCO-2 RNHCO2H K10 Introduction RNH+3 K5 RNH2 Thermostatting Ionic Strength pH Application CO2 User interface based on Excel, model parser Introduction Thermostatting Ionic Strength pH Application CO2 Example 1: Ammonia, NH3 Introduction Thermostatting Ionic Strength pH Application CO2 Measurements, stopped-flow [CO2] = 3.8 mM [NH3] = 2-10 mM [ThB] = 12.5 M 0.9 0.4 0.8 Abs @ 590 nm 0.3 Abs @ 590 nm 0.7 0.6 10 mM 0.2 0.1 2 mM 0.5 0 0 0.5 0.4 1 1.5 2 time, s 0.3 10 mM 8 mM 0.2 6 mM 0.1 4 mM 2 mM 0 0 3 mM 20 40 60 80 time, s Introduction Thermostatting Ionic Strength pH Application CO2 Measurements, stopped-flow [CO2] = 3.8 mM [NH3] = 3 mM [ThB] = 12.5 M different temp. Abs @ 590 nm 0.4 0.3 0.2 0.1 o o 45 C o 35 C 25 C 0 0 10 20 30 40 time, s Introduction Thermostatting Ionic Strength pH Application CO2 Analysis: NH3 + CO2 NH4+ NH3 log(concentration) HCO3- CO32NH2CO2- CO2 NH4+ Concentration (M) NH3 NH2CO2H HCO3- NH4+ CO2 NH2CO2CO32- Concentration (M) NH3 CO2 HCO3- NH2CO2- CO32- Introduction Thermostatting Ionic Strength pH Application CO2 Measurements, stopped-flow [NH3] = 44 mM [HCO3-] = 94 mM equilibration [NH3] = … M [HCO3-] = … M [NH2COO-] = … M [HCl] = 65 mM [BTB] = 12 M [AlRed] = 50 M different temp 0.4 45 oC Abs @ 520 nm 35 oC 25 oC 0.3 15 oC 0.2 0.1 0 0 0.3 0.6 0.9 1.2 1.5 time, s Introduction Thermostatting Ionic Strength pH Application CO2 Analysis: NH2COO- + H+ HCO3NH4+ CO2 NH4+ CO2 NH2CO2- log(concentration) Concentration (M) HCO3- H2CO3 NH3 CO32NH2CO2NH2CO2H H+ H2CO3 log(time) Introduction Thermostatting Ionic Strength pH Application CO2 Very important aspect: all measurements were analysed together, global analysis! There are no experimental conditions where one experiment contains sufficient information for a fit of the model. Introduction Thermostatting Ionic Strength pH Application CO2 The Results: rate and equilibrium constants as a function of the temperature T [oC] k7 [M-1 s-1] k-7 [s-1] 15.0 23.5(3) 4.6(1) 10-3 9.3(9) 25.0 49(6) 1.3(1) 10-2 35.0 69(5) 2.3(1) 45.0 97(14) 4.4(7) T [oC] Introduction k8 [M-1 s-1] k-8 [s-1] k9 [M-1 s-1] 10-4 2.8(3) 10-4 2.07(1) 1.4(2) 10-3 6.0(9) 10-4 4.5(1) 10-2 2.5(6) 10-3 1.3(3) 10-2 6(2) 10-3 K7 [M-1] 5(1) 10-3 10-3 102 102 k-9 [s-1] logK10 32.2(5) 6.71(2) 84(16) 6.73(7) 9.25(4) 102 1.88(5) 1.53(6) 103 3.8(3) 102 102 6.70(2) 6.88(4) K8 [M-1] K9 [M-1] 15.0 5.1(1) 103 3.3(1) 6.4(1) 25.0 3.7(6) 103 2.29(4) 5.6(9) 35.0 3.0(1) 103 2.02(3) 4.9(1) 45.0 2.2(2) 103 1.05(5) 4.0(3) Thermostatting Ionic Strength pH Application CO2 The Results: Arrhenius and van t’Hoff plots 10 8 6 6 lnk 9 4 4 lnk 7 2 ln(k -i) lnk i 8 2 0 -2 0 -2 -6 lnk 8 -6 0.0032 0.0033 0.0034 Thermostatting ln(k - 8) -8 0.0035 -10 0.0031 1/T Introduction ln(k -7 ) -4 -4 -8 0.0031 ln(k - 9) 0.0032 0.0033 0.0034 0.0035 1/T Ionic Strength pH Application CO2 The Results: complete set of thermodynamic parameters Arrhenius Ea A [kJ mol ] k7 NH 3 +HCO 3- k - NH 2 COO +H 2 O NH 3 +CO 2 NH 2 COOH Introduction k9 k mol-1] K-1] 33(2) -104(7) 56(2) 6.9 10 7 53(2) -103(7) NH 2 COO - +H 2 O 45(4) 1.2 105 42(4) -156(12) - 72(5) 2.8 10 9 70(5) -72(2) 51(1) 4.2 1011 49(1) -31(3) 7.7 12 7 8 H 2 CO 3 +NH 3 NH 3 +HCO 3 NH 2 COOH 9 [J mol-1 107 k k8 [kJ 6.0 NH 2 COOH+H 2 O NH 2 COOH+H 2 O S‡ ‡ -1 NH 3 +H 2 CO 3 van’t Hoff Eyring NH 3 +CO 2 Thermostatting 35(2) 63(2) 10 Ionic Strength 60(2) S [kJ mol-1] [J mol-1 K1 ] -21(2) -1(5) -27(2) -84(7) -59(8) -152(26) -7(6) pH Application CO2 Example 2: morpholine O H2C CH2 H2C CH2 N H Introduction Thermostatting Ionic Strength pH Application CO2 1H-NMR O H2C CH2 H2C CH2 spectra morpholine N H O H2C CH2 H2C CH2 N COO- morpholine + carbamate Introduction Thermostatting O O H2C CH2 H2C CH2 O H2C CH2 H2C H2C CH2 H2C CH2 N N COO- COO- N H Ionic Strength CH2 O H2C CH2 H2C CH2 N H pH Application CO2 spectra of Morpholine at 25˚C (Morpholine/Na2CO3 1/2 with different volumes of 5M HCl) 1H-NMR O O H2C CH2 H2C CH2 H2C CH2 H2C CH2 N N H2+ COO- 0.1 0.09 0.08 0.07 0.06 0.05 4.5 0.04 O H2C 4 CH2 0.03 0.02 3.5 0.01 3 H2C CH2 2.5 Introduction 0 vol added (mL) ppm N H Thermostatting Ionic Strength pH Application CO2 Analysis of the data Calculated Vs Measured Concentrations 0.025 Concentration (M) 0.02 0.015 0.01 0.005 0 6 7 8 9 10 11 pH Introduction Thermostatting Ionic Strength pH Application CO2 Collaborations with • Department of Chemistry, University of Newcastle, Australia Prof. Geoff Lawrance Dr. Bob Burns Dr. Raylene Dyson Dr. Nichola McCann Dr. Sarah Norman Dr. Xiaoguang Wang Will Conway Debra Fernandes Azadeh Golshan Yaser Beyad • Institute of Inorganic Chemistry, University of Basel, Switzerland Prof. Andreas Zuberbühler • Institute for Chemical and Bioengineering, ETH Zürich, Switzerland Dr. Yorck-Michael Neuhold Prof. Konrad Hungerbühler • University of Kaiserslautern Prof. Hans Hasse Dr. Nichola McCann • CSIRO Energy Technology, Newcastle, Australia Dr. Graeme Puxty Dr. Paul Feron Thank you for your attention
Similar documents
htr_main (jielde)
The Synthesis of Ethyl 2-(2-Cyano-2-ethoxycarbonylethenyl)amino-3-dimethylaminopropenoate. The Synthesis of Substituted Aminoazolo-, Aminoazinopyrimidinones and 2H-1-Benzopyran-2-ones
More information