bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Structures of Sodium Phenylhydrazides
Authors: Knizek Jörg , Krossing Ingo , Nöth Heinrich , Schwenk Holger , Seifert Thomas 
Published: July 2007

AbstractMonomeric Li(Ph)NN(Ph)SiMe3 · 2 OEt2 was obtained by deprotonating the respective hydrazine with nBuLi in the presence of diethyl ether. Reaction of NaN(SiMe3)2 with PhHN−N(SiMe3)2 in a benzene/tetrahydrofuran mixture provided monomeric Na(Ph)NN(SiMe · 3 THF, or Nd(Ph)NN(SiMe3)2 · THF using a small amount of THE Its TI IF ran be replaced by diethyl ether or tert‐butyl methyl ether to give 1:l solvates. These associate, forming chains in the solid state via ηn coordination (n = 2, 3) of their phenyl groups to the sodium centers of adjacent molecules. In contrast, not only deprotonation but also desilylation occurs on reaction of NaN(SiMe3)2 with H(Ph)NN(Ph)SiMe3 or of NaNH2 with (Me3Si)HNNPh2) The latter reaction results in the formation ot hexameric (NaHNNPh2)6 which adopts a face‐sharing double‐cubane structure.
Synthetic Routes to Transition‐Metal‐Substituted Pentadiynylidene Complexes
Authors: Hartbaum Cornelia , Fischer Helmut 
Published: July 2007

AbstractSequential reaction of the dimethylamino(ethynyl)carbene complex [(CO)5 WC(NMe2)CCH] (1) with nBuLi, CuI and BrCCSiMe3 affords the dimethylamino(trimethylsilylbutadiynyl)carbene [(CO)5WC(NMe2)CCCCSiMe3] (2). Desilylation of 2 with KF/THF/MeOH gives [(CO)5WC(NMe2)CCCCH] (3). The C‐stannylated carbene complex [(CO)5WC(NMe2)CCCCSnBu3] (4) is obtained by deprotonation of 3 with nBuLi and subsequent reaction with Bu3SnCl. Pd‐catalyzed coupling of complex 4 with [ClRu(CO),Cp] affords the heterobimetallic pentadiynylidene complex [(CO)5WC(NMe,)CCCCRu‐(CO)2Cp] (5) The analogous Fe derivative [(CO),WC(NMe,)CCCCFe(CO)2Cp] (6) is obtained by sequential reaction of 3 with nBuLi and [IFe(CO)2Cp] Similarly, treatment of 3 first with nBuLi and then with half an equivalent of HgCl2 affords the novel C4HgC4‐bridged biscarbene complex [(CO)3WC(NMe2)CCCCHgCCCCC(NMe2)W(CO)5]( 7 ) All new compounds are stable at room temperature. Spectroscopic data suggest weak interaction of the metal centers in 5 – 7.
Isolation and Characterization of a Porphinatomanganese(IV) Complex from the Reaction of Dichloro Monoxide with 5,10,15,20‐Tetrakis‐(2,6‐dichloropheny)porphinatomanganese(III) Chloride [Mn(EDCPP)CI]
Authors: Volz Heinrich , Müller Wihelm 
Published: July 2007

AbstractThe isolation at −78°C and characterization of the novel crystalline reactive porphinatomanganese(IV) complex Mn‐(TDCPP)(OCl)2(5) is described.5is compared with the porphinatomanganese(IV) complexes Mn(TDCPP)(C6H5IOCl)2(2), Mn(TDCPP)(C6F510C1)CI (3) and Mn(TDCPP)(OCH3)2, (4). The stoichiometric reaction of5with triphenylphosphane yields 2.5 equivalents of triphenylphosphane oxide and 1.0 equivalent of Mn(TDCPP)Cl (1). Complex5epoxidizes stilbene, and oxygenates and chlorinates cyclohexane.
A Decavandate Sandwiched by Diprotonated Cryptands‐222: Model for the Vanadate‐Ionophore Interaction
Authors: Farahbakhsh Mahin , Schmidt Häke , Rehder Dieter 
Published: July 2007

AbstractTreatment of a C222‐vanadyl‐AMP complex (C222 = cryptand‐222, AMP = adenosine monophosphate) with Me2NH in the presence of air yielded centrosymmetric dihydrogen‐decavanadate H2V10O428, sandwiched by two diprotonated C222 molecules. An X‐ray crystal‐structure analysis was performed of this compound with the overall composition [C222(H+)2]2[H2V10O28] · 2 1/2, H2O. Protonation sites in the anion are μ2‐oxygen atoms linking two different vanadium centres. Protonation sites at the cryptand are the nitrogen and/or oxygen atoms of one of the −[CH2]2O[−CH2|2O|CH2]– bridges. The relevance of the compound for the stabilisation and transport of the kinase and phosphatase inhibitor decavanadate by biogenic ionophores is addressed.
Raman and Infrared Spectra and Quantum Chemical Calculations for Trichlorophosphoranylidenesulfamoyl Chloride, CISO2N=PCI3
Authors: áglvarez R. M. S. , Cutin E. H. , Mack H.‐G. , Della Védova C. O. 
Published: July 2007

AbstractRaman (3500‐50 cm−l) and infrared (4000‐400 cm−l) spectra of the title compound, ClSO2NPCl3, were recorded for the solid and liquid phase. Additionally, the Raman spectrum of the compound dissolved in CCl4 was obtained and qualitative depolarization values were determined. The spectra of the liquid and solid phase were interpreted in terms of the existence of only one conformation possessing C1 symmetry, as predicted by quantum chemical calculations. A complete vibrational assignment is proposed based on the relative intensities, on group frequencies along with support from the normal coordinate analysis. The experimental fundamental vibrational modes are compared to those obtained from theoretical approaches employing the ab initio MP2/6‐31G* method and a density functional approximation (B3PW91/6‐31G*).
A New Efficient Synthesis of the Stilbenoid Laser Dyes BPS and Stilbene I by Palladium‐Catalyzed Coupling of Ethene with Bromoarenes
Authors: Rümper Jörg , Sokolov Viktor V. , Rauch Karsten , Meijere Armin De 
Published: July 2007

AbstractThe palladium‐catalyzed coupling of ethene with 4‐bromobiphenyl and 4′‐bromo‐4‐biphenylsulfonic acid permits a facile one‐pot preparation of the laser dyes (E)−4,4′‐diphenylstilbene (BPS, 3) and bis(triethylammonium) (E)−4,4′diphenylstilbene‐4″,4″‐disulfonate (6) in diastereomerically pure form on a multigram scale, with yields of 69 and 64%, repectively. The latter can easily be transformed to its dipotassium salt 7, the Stilbene I dye.
Synthesis, Redox Chemistry, and Mixed‐Valence Phenomena of Cyanide‐Bridged Dinuclear Organometallic Complexes
Authors: Zhu Nianyoung , Vahrenkamp Heinrich 
Published: July 2007

Abstract21 new organometallic complexes of the type M–Cn–M′ containing the building blocks M, M′ = (CO)5Cr, (CO)5Mo, (CO)5W, Cp(CO)2Mn, Cp(CO)2Fe, Cp(CO)(CN)Fe, Cp(dppe)Fe, Cp(PPh3)2Ru, Cp(PPh3)Ni, and (PPh3)2Ag were obtained from the reagents M–Cn and M–X (X = leaving group). Among them are five pairs of linkage isomers M–CN–M′/M–NC‐M′. Structure determinations of (CO)5Cr–CN–M′ with M′ = Fe(dppe)Cp, Ni(PPh3)Cp, Ag(PPh3)2 and of (CO)5Cr–NC‐Fe(dppe)Cp have proved their identity and the linkage isomerism. Systematic variations of the v(CN) and v(CO) IR bands allow as assessment of the relative electron pair acceptor strengths of the building blocks M and M′ and a reliable identification of the individual linkage isomers. All dinuclear complexes are redox‐active, showing at lease one reversible oxidation. The redox potentials are characteristically dependent upon the nature of the building blocks M and M′ and upon the orientation of the cyanide link (CN vs. NC), 6 oxidized complexes of the type [M–Cn–Fe(dppe)Cp]+ were prepared chemically and isolated as PF6 or BF4salts. The molecular structure of [(CO)5Cr–CN–Fe(dppe)Cp]BF4 is not significantly different from those of the corresponding neutral Cr–CN–Fe or Cr–NC‐Fe complexes. Upon oxidation the v(CN) band of the complexes shifts to lower wavenumbers and becomes much more intense. The oxidized complexes show the paramagnetism due to one unpaired electron. They give rise to very intense metal‐to metal charge‐transfer bands in the near infrared region whose position was found to be characteristically dependent on solvent polarity of [(CO)5Cr–CN–Fe(dppe)Cp]BF4. A semiquantitative treatment of the optical and electrochemical measurements shows that the electron delocalization and metal–metal interaction in the oxidized dinuclear complexes is significant and that they belong to the class‐II mixed‐valence systems.
Evidence for Internal Ion Pair Formation upon Insertion of Reactive Alkene in the Zirconium–Carbon Bond of the cp2Zr(μ‐C4h6)b(c6f5)3 Metallocene‐Boron‐Betaine Ziegler Catalyst System
Authors: Karl Jörn , Erker Gerhard 
Published: July 2007

AbstractTreatment of the (butadiene)ML2 complexes 1 [ML2 = Cp2Zr (a), Cp2Hf (b), and (.‐C5H4CH3)2Zr (c)] with B(C6F5)3 gives the 1:1 addition products (CH2CHCHCH2–B(C6F5_3)ML2 (3a–c). At –40°C the betaine complex 3a inserts one equivalent of methylenecyclopropane to give the regioisomeric insertion products 5a and 6a in a 60:40 ratio. These products exhibit the cyclopropylidene moiety in the α‐ and β‐positions, respectively, relative to zirconium. The corresponding hafnocene complexes 5b and 6b are obtained in a 70:30 ratio starting from 3b. The reaction of 3(a–c) with allene gives a single insertion product (7a–c) in each case where the exo‐methylene group is in the α‐position to the metal center ([2,1]‐insertion). The complexes 5–7 are chiral. They all exhibit a pronounced ·‐interaction of the internal –C4H=C5H− double bond of the s̀‐ligand chain with the metal center in addition to a metallocene/–C6H2–[B] ion pair interaction. The relative contributions of the cationic metallocene end of the dipolar complexes 5–7 are quite dependent on the steric and electronic properties of the respective metallocene units involved. This is revealed by a comparison to typical 13C‐NMR parameters of the complexes 5–7 with a pair of suitable model complexes, namely the ethylene insertion product 4 into the betaine system 3a and its THF adduct 4.THF.
Transition‐Metal‐Substituted Acylphosphanes and Phosphaalkenes, 35 Unprecedented Coupling of a Transition‐Metal Carbyne and a Methylene Phosphane Moiety – Structure of [Tp'(CO)2W=CP=C(NEt2)2] [Tp = HB (3,5‐Me2HC3N2)3]
Authors: Weber Lothar , Dembeck Gottfried , Boese Roaldn , Bläser Dieter 
Published: July 2007

AbstractCondensation of [Tp](CO)2 Mčl] [1: M = Mo; 2: W; Tp] HB (3,5‐Me2HC2N2)3] with the inverse phosphaalkenes Me3 Sip=C(NR2)2 (3a: R = Me; 3b: Et) affords the novel phosphaalkenyl carbyne complexes [Tp](CO)2M.C–P=C(NR2)2] (a, b) (M = Mo; R = Me, Et) and 5a, b (M = W; R = Me, Et), which have been characterized by IR, 1H‐, 13C‐ and 31P‐NMR spectroscopy. In additon, the molecular structure of 5 has been elucidated by a single‐crystal X‐ray structure determination.
Coordination Polymers, 13. Induction of Helicity via Stereogenic Centers: Asymmetric Synthesis of (P)‐ and (M)‐Coordination Polymers
Authors: Saalfrank Rolf W. , Decker Michael , Hampel Frank , Peters Karl , von Schnering Hans Georg 
Published: July 2007

AbstractReaction of a methanolic copper(II) acetate solution of enantiomerically pure (5R)‐/(4S)‐methyl E‐(4‐ethyl‐2‐oxazolidinylidene)cyanoacetate 6 leads to the mononuclear chelate complexes (R, R)‐/ (S, S)‐7. Recrystallization of (R, R)‐/(S, S)‐7 from non‐coordinating chloroform and asymmetric induction via the stereogenic centers, originating from (R)‐/(S)‐6, stereospecifically yield the right‐ and left‐handed helical ID‐coordination polymers (P)‐/(M)‐8. The structures of mononuclear complex (R, R)‐7 and of helix (P)‐8 and its mirror image (M)‐8 have been characterised unequivocally by X‐ray crystal structure analyses. (P)‐ and (M)‐8 crystallize with chloroform to give the clathrates 1.{[CuLR2]. 2 CHCl3} and 1.{[CuLS2].2CHCl3}, respectively.
Chiral Arene Ruthenium Complexes, 2 A Diastereoselective Route to [η6‐Benzyl Alcohol)(COD)Ru] Complexes
Authors: Bodes Gegro , And Frank Heinemann , Zenneck Ulrich 
Published: July 2007

AbstractTwo preparative routes are reported that give access to the racemic series of planar chiral [(arene)(COD)Ru] derivatives containing η6‐bonded o‐tolyl ketone or aldehyde arene units. The ketone and aldehyde functions of these have subsequently been reduced by nBuLi and PhLi, respectively. Hydrolysis converts the initially formed lithium salts into diastereomeric benzyl alcohol complexes lithium salts into diastereomeric benzyl alcohol complexes in high yields. The formation of the new stereogenic centre is diastereoselective (88% de) for the aldehyde and diastereospecific for the ketone (de > 99%). Due to a sterically overcrowded situation, the rotation of the chiral side chain of [(COD) (η6–o‐tolyl‐tert‐butylphenylmethanol) Ru] (7) is hindered, as is the rotation of the phenyl and tert‐butyl substituents. As a consequence, the hydroxyl group is fixed at a position close to the metal both in solution and in the solid state.
Neutral Gold(I) Complexes with Mixed Phosphorus Ligands
Authors: Hollatz Christian , Schier Annette , Schmidbaur Hubert 
Published: July 2007

AbstractThe reaction of compounds (R3P) AuMe with diphenylphosphinous acid Ph2P(O)H affords methane and neutral complexes of the type (R3P(O)Ph2 (1a: R = Me; 1b: R = Ph, lc: R = o‐Tol). 1a, b are obtained in high yield, but the yield of lc is lower owing to a side‐reaction which leads to a different product: Ph2P(OH)–Au–P(O)Ph2 (2). The crystal structure of 1a was determined by a single‐crystal X‐ray diffraction study. The compounds is a monomer with a linear P–Au–P′ axis and the phosphane and phosphinite ligands in a staggered conformation. In solution (CHCl3, CH2Cl 2/) compounds 1a–c undergo a ligand redistribution, establishing equilibria that involve ionic isomers of the type [R3P)2Au]+ [Au‐(P(O)Ph2)2]−, which are readily identified through their NMR data. The analogous reaction of (R3P)b AuMe with dimethylphosphite (MeO)2P(O)H gives methane and the corresponding dimethylphosphites of the type (R3P)AuP(O)(OMe)2 (3a: R = Me; 3b: R = Ph; 3c: R= o‐Tol). The crystal structure of 3b has also been determined. It features a linear structure with an eclipsed conformation of the ligands. In polar solvents (CHCl3, methanol) there is again an eqilibrium between neutral and ionic isomers, the latter comprising bis(phosphane)gold cations [(R3P)2Au]+ and {Au[P(O)‐(OMe)2]2)− anions, as confirmed by NMR spectroscopy and mass spectrometry.
Synthesis and Structural Characterization of Mixed‐Ligand Oxorhenium(V) Complexes Containing Bidentate Dithioethers and Monothiolato Ligands
Authors: Reisgys Martina , Spies Hartmut , Johannesn Bernd , Pietzsch Hans‐Jergen , Leibnitz Peter 
Published: July 2007

AbstractNeutral oxorhenium(V) complexes with dithioether ligands of the general formula [ReOX3(RS[CH2]2SR)], × = Cl, Br, R = nBu, Et, Bzl were synthesized. Ammonium perrhenate reacts in concentrated hydrochloric acid with dithiaalkanes (RS[CH2]2SR, R =nBu, Et, Bz) dissolved in glacial acetic acid to give octahedral complexes of the type [ReOCl3(RS[CH2]2SR)] (1a–c). In concentrated hydrobromic acid, nBu–S(Ch2)2S–nBu leads to the corresponding tribromo complexes (2). The X‐ray structure of shows a distorted octahedron with facial coordination of the bromide ligands. The sulfur atoms are cis coordinated to the terminal oxygen. Dissolution o f1a (R = nBu) in methanol leads to the substitution of the chloride trans to the oxo ligand by a meth oxy group. The resultant complex [ReOCl2(MeO) (nBu–S[CHL2]2S–nBu)] (3) is stable and can be isolated from methanolic solution, but changes to the μ‐oxo‐bridged dirhenium complex μ‐oxobis[dichloro(5,6‐dithiadidodecane)oxorhenium(V)] (4) when dissolved in other organic solvents. 1a reacts with an excess of benzenethiol by substitution of two chlorides to give the mixed‐ligand complex bis(benzenethiolate)chloro(5,8‐dithiadodecane)oxorhenium(V) (5a). The related 4‐methylbenzenethiolato complex 5b was synthesized starting from the μ‐oxo complex 4. X‐ray crystal structure determination of 5b shows the equatorial arrangement of the sulfur atoms. The trans position to the oxygen atom is occupied by a chloride ion.
Organo‐Substituted 1,2‐Dihydro‐1,2,5‐Disilaborepines
Authors: Wrackmeyer Bernd , Maisel Heidi E. , Milius Wolfgang 
Published: July 2007

Abstract1,2‐Di‐1‐propynyl‐tetramethyldisilan (1) reacts with triorganoboranes R3B [R = Et (2a), CH2Ph (2c), 2‐thienyl (2d)], 9‐ethyl‐9‐borabicyclo[3.3.1]nonane (3), and diethyl(N‐pyrrolyl)borane (4) by twofold 1,1‐organoboration to give selectively the respective organo‐substituted 1,2‐dihydro‐1,2,5‐disilaborepines 5a‐d,6, and 7 in high yields. The compounds 5–7 were characterized by 1H‐, 11B‐, 13C‐, and 29Si‐NMR spectroscopy in solution. The molecular structures of the distance 1 and of the heterocycle 5c were determined by X‐ray structure analysis.
Troponin, B‐type natriuretic peptides and outcomes in severe heart failure: Differences between ischemic and dilated cardiomyopathies
Authors: Miller, Wayne L. , Hartman, Karen A. , Burritt, Mary F. , Burnett John C. , Jaffe, Allan S. 
Published: July 2007

AbstractBackgroundIschemic (ISCM) and idiopathic dilated (IDCM) cardiomyopathies have different responses to therapy and outcomes. Both may demonstrate elevations in troponin and B‐type natriuretic peptides, but biomarker levels have not been reported to differ as a function of the etiology of heart failure (HF). Accordingly, we compared these biomarkers in patients with chronic HF.HypothesisBiomarker levels of troponin T, troponin I, B‐type natriuretic peptide (BNP), and N‐terminal prohormone brain natriuretic peptide (NT‐proBNP) are quantitatively different between ischemic and idiopathic dilated etiologies of chronic HF.MethodsForty patients (27 male, 68 ± 2 years; LVEF 25 ± 1%; NYHA Class III–IV) admitted to hospital for acute HF were studied. Biomarkers were drawn at admission prior to treatment intervention.ResultsOf the 40 patients, 27 had ISCM and 13 IDCM. Baseline clinical characteristics were similar with the exception of GFR. cTnT, cTnI, and BNP levels were higher in ISCM patients (cTnT: 0.373 ± 0.145 vs. 0.064 ± 0.016 ng/mL, p < 0.05; cTnI: 2.02 ± 0.76 vs. 0.21 ± 0.11 ng/mL, p < 0.05; BNP: 776 ± 91 vs. 532 ± 85 pg/mL, p < 0.05). Cardiovascular mortality during follow up (10 ± 1 months) was 48% in patients with ISCM and 23% with IDCM (p < 0.05).ConclusionsPatients with acutely decompensated chronic HF have elevations in troponin and BNP. These elevations, as well as mortality are significantly higher in patients with ISCM compared to IDCM. The differential levels in biomarkers may be due to differences in disease pathogenesis, and fit with the adverse prognosis in these patients. Copyright © 2007 Wiley Periodicals, Inc.
Characteristics and in‐hospital mortality of diabetics and nondiabetics with an Acute Coronary Syndrome; the GREECS study
Authors: Pitsavos, Christos , Kourlaba, Georgia , Panagiotakos, Demosthenes B. , Stefanadis, Christodoulos 
Published: July 2007

AbstractObjectivesIn this work, we sought to describe the baseline characteristics and the management of patients with and without diabetes hospitalized with acute coronary syndromes (ACS), as well as to assess the prognostic value of diabetes status to the severity of ACS and in‐hospital mortality.MethodsA sample of six hospitals located in Greek urban and rural regions was selected and we recorded almost all admissions due to ACS, from October 2003 to September 2004. 2,172 patients were included in the study. Socio‐demographic, clinical, dietary and other lifestyle characteristics was recorded.ResultsApproximately 1 in 3 patients admitted at the hospital with ACS had history of diabetes. Diabetes mellitus was associated with old age, female gender and more prevalent history of coronary heart disease, hypertension and renal failure. Diabetics sought medical care later and they were less likely to receive fibrinolytic therapy. No statistically significant difference was observed on severity of ACS between diabetics and nondiabetics. The in‐hospital mortality was higher in diabetics compared to nondiabetics. In a multivariate analysis only insulin‐treated diabetics had an increased mortality rate compared to nondiabetics.ConclusionsThe use of more effective medications and interventions must be used in diabetics who develop ACS, as well as educational efforts should be directed to those patients for reducing the pre‐hospital delay. Copyright © 2007 Wiley Periodicals, Inc.
QT dispersion and prognosis after coronary stent placement in acute myocardial infarction
Authors: Ueda, Hiroyasu , Hayashi, Tomoshige , Tsumura, Kei , Kaitani, Kazuaki , Yoshimaru, Kiyomichi , Nakayama, Yasunori , Yoshiyama, Minoru 
Published: July 2007

AbstractBackgroundQT dispersion is increased in acute myocardial infarction (AMI), but the relation of QT dispersion to prognosis has not yet been fully elucidated.HypothesisThe purpose of this study is to evaluate prospectively whether QT dispersion is associated with the risk of major adverse cardiac events (MACEs) and mortality after successful coronary stenting in AMI.MethodsOne hundred and forty‐two patients with AMI and undergoing successful percutaneous coronary intervention (PCI) were enrolled in this study. Corrected QT dispersion was measured before and 24 h after PCI.ResultsDuring a period of 4477 person‐months, we confirmed 21 cases of MACE. Univariate analysis indicated that corrected QT dispersion before and 24 h after PCI, age, number of Q waves, and Killip > 2 were related to MACE and mortality. By multivariate analysis, corrected QT dispersion before PCI was an independent predictor of MACE and mortality, but corrected QT dispersion at 24 h after PCI was not statistically associated with MACE and mortality. Multiple‐adjusted hazard ratios for a 1 standard deviation (SD) magnitude increase in corrected QT dispersion before PCI were 2.24 (95% confidence interval, 1.36–3.68, p = 0.001) for MACE and 2.71 (95% confidence interval, 1.50–4.89, >) for mortality after adjustment for age, gender, ejection fraction, and Killip > 2.ConclusionsCorrected QT dispersion before PCI is associated with an increased risk of MACE and mortality after successful PCI in patients with AMI. Copyright © 2007 Wiley Periodicals, Inc.
Influence of Intermolecular Interactions on the Formation of Tetra(carbomethoxy)‐tetrathiafulvalene Assemblies
Authors: Crivillers Núria , Mas‐Torrent Marta , Bromley Stefan T. , Wurst Klaus , Veciana Jaume , Rovira Concepció 
Published: July 2007

AbstractWe study the assemblies that tetra(carbomethoxy)tetrathiafulvalene (TCM–TTF) forms in solution and when deposited on a surface depending on intermolecular interactions and on the interactions with the substrate and the solvent. Its organization on graphite and mica substrates was studied by atomic force microscopy, and different molecular assemblies were observed depending on the prevailing interactions. The promotion of molecule–molecule interactions gave rise to the formation of molecular fibers. The investigation of the influence of the solvent–molecule interactions on TCM–TTF molecular organizations was carried out by UV/Vis spectroscopy, and a new TCM–TTF polymorph was obtained by changing the nature of the solvent. Finally, an explanation for all these phenomena, supported by computational modeling, is put forward.
Nonideal performance of analogue discrete networks
Authors: Bruton L. T. , Haslett J. W. , Atkins R. C. 
Published: July 2007

AbstractAnalogue delay lines, in the form of charge‐coupled or bucket‐brigade devices, are important network elements that may be used in connection with gain elements and summer–subtractor elements to realize microelectronic filters. This paper establishes invariant lower bounds on the sensitivity of the input–output transfer function to perturbations of the gains and delays of the analogue delay lines. Conventional sensitivity criteria, known as the Worst‐case and Schoeffler criteria, are used to represent the nonideal deviation of the transfer function.It is demonstrated that, insofar as tolerance limitations are concerned, the conventional direct‐form structure (which is extensively employed to realize charge‐coupled‐device filters), is far inferior to the ladder structure.
Using least‐mean‐square‐approximation technique in filter design
Authors: Rakovich B. D. 
Published: July 2007

AbstractThe applications of the least‐mean‐square‐approximation technique to filter synthesis are discussed, and explicit expressions for the characteristic function of all‐pole lowpass filters are derived using a weighted least mean‐square error norm. The weight function depends on one variable parameter which controls the shape of the magnitude response both in the passband and in the stopband. It is shown that most of the filter functions in common use are special cases of this approximation procedure, including Legendre monotonic passband filters as a limiting, degenerate case. Also, a useful generalization of Legendre filter functions is proposed.