Joel Bernstein: a crystal engineer's crystal engineer

Joel Bernstein was a gentle giant in the field of organic solid‐state chemistry and a person who inspired anyone who was in his presence and attended his charismatic lectures over the five decades of his academic career. This commentary looks at his scientific publishing career.     

Nd2O3·BaO·Al2O3·6B2O3的晶体结构

Nd_2O_3·BaO·Al_2O_3·6B_2O,晶体属六方晶体系,空间群为D_h-P62m晶胞参数a=4.566(2)A.Z=24.92(1)A,Z=1。由PW1100四园衍射仪收集到1460个独立衍射强度,用SNELX-76程序中的直接法解得晶体结构,全矩阵最小二乘方法修正结构参数,最后得到偏离因子R=8.80％(未校正吸收),全部计算在SORDCP/M-68K微处理机上完成,晶胞中2/3的B原于位于四面体内,形成[B_2O_5]~4-团,另外1/3的B原子,连结33个O原子形成[B_2O_3]中性团。由对称面联系的[B_2O_3]团的B与B原子之间借助范德华键键合,结构上的这一特点,与硼酸铝钡钕晶体垂直C轴方向有明显解理性质完成一致。这一晶体的结构式可表示为Nd_2BaAl_2O_(1-x)[B_2O_5]_4[B_4O_(4+x+(2-x))]     

Turning on Solid‐State Fluorescence with Light

A bioinspired fluorophore that is analogous to the substrate in the bioluminescence of fireflies was prepared and reacts when exposed to weak blue LED light. Upon excitation, this material is photodecarboxylated with a nearly 81‐fold enhancement of the solid‐state emission, the fluorescence quantum yield of the product in solution is approximately 90 %, and violent disintegrative effects occur as a result of the release of carbon dioxide. Crystallographic and computational results, together with global spectral analysis of the kinetics, confirmed that most of the emission observed in the decay‐associated spectra is intrinsic to the product molecule, with only a minor contribution from an excimer through π–π stacking of the molecules in the crystal.     

Phase transition of Fe(dpm)<Subscript>3</Subscript> in the range 243–210 K

The volatile Fe(dpm)₃ complex was studied by X-ray diffraction at 243 K and 210 K. A phase transition from monoclinic to triclinic structure was found in the temperature range 236–226 K. The packing of complexes in the structures is analyzed by the procedure of translation sublattice isolation. The motif of mutual arrangement of Fe atoms is pseudohexagonal in both modifications. Apart from the differences in the Fe...Fe distances, there are differences in rotation of definite chelate rings.     

Glenn T. Seaborg; discoveries; and the capital of knowledge

Ten years from Glenn T. Seaborg’s death we remember his achievements; his teaching about the importance of basic research is as timely as ever.     

Dalton’s Disputed Nitric Oxide Experiments and the Origins of his Atomic Theory

In 1808 John Dalton published his first general account of chemical atomic theory, a cornerstone of modern chemistry. The theory originated in his earlier studies of the properties of atmospheric gases. In 1803 Dalton discovered that oxygen combined with either one or two volumes of nitric oxide in closed vessels over water and this pioneering observation of integral multiple proportions provided important experimental evidence for his incipient atomic ideas. Previous attempts to reproduce Dalton’s experiments have been unsuccessful and some commentators have concluded the results were fraudulent. We report a successful reconstruction of Dalton’s experiments and provide an analysis exonerating him of any scientific misconduct. But we conclude that Dalton, already thinking atomistically, adjusted experimental conditions to obtain the integral combining proportions.     

Crystal structure of copper(II) <Emphasis Type="Italic">trans</Emphasis>-bis-(4-phenyliminopentan-2-onate)

trans-Bis-(4-phenyliminopentan-2-onato)Cu(II) (5), which is a phenyl-substituted ketoimine, was synthesized, and an X-ray study was performed for this compound. Crystal data for CuN₂O₂C₂₂H₂₄: a = 11.4557(3) Å, b = 26.6845(9) Å, c = 14.2976(5) Å, β = 113.2270(10)°; space group P2₁/n, Z = 8, d _calc = 1.363 g/cm³, R = 0.033. The structure is molecular and built of isolated trans complexes. The central copper atom is surrounded by four atoms (2O+2N) with the average distances Cu-O 1.904(3) Å and Cu-N 1.962(3) Å. The polyhedron around the copper atom is a distorted tetrahedron; the average values of the O-Cu-O and N-Cu-N trans bond angles are 147(2)° and 150(2)°, respectively. The average value of the O-Cu-N angles is 94(1)°.     

Homochiral conglomerates and racemic crystals in two dimensions: tartaric acid on Cu(110)

Two-dimensional lattice structures formed by racemic tartaric acid on a single crystalline Cu(110) surface have been studied and compared with the enantiopure lattices. At low coverage, the doubly deprotonated bitartrate species is separated into two-dimensional conglomerates showing opposite enantiomorphism. At higher coverage, however, a singly deprotonated monotartrate species forms a heterochiral, racemic crystal lattice. While the enantioseparated bitartrate system undergoes decomposition at the same temperature as the enantiopure system, the racemic monotartrate lattice has a lower thermal stability than the enantiopure lattice of identical periodicity and surface density. At monolayer saturation coverage, the pure enantiomers form a denser lattice than the racemate. This is in contrast to the three-dimensional tartaric acid crystals, where the racemate crystallizes in a lattice of higher density, which is also more thermally stable than the enantiopure tartaric acid crystals.     

Crystal and molecular structure of copper(II) <Emphasis Type="Italic">trans</Emphasis>-bis-(2-(methylimino)-4-pentanonate)

Synthesis and X-ray diffraction study of trans-bis-(2-(methylimino)-4-pentanonato)Cu(II), which is methyl-substituted ketoiminate, is reported. Crystal data for CuN₂O₂C₁₂H₂₀: a = 7.374(1) , b = 9.171(1) , c = 10.823(2) ; = 96.51(1)°, = 106.12(1)°, = 96.81(1)°, space group P , Z = 2, d _calc = 1.38 g/cm³, d _exp = 1.37 g/cm³, R = 0.037. The structure is molecular and consists of isolated trans-complexes. The coordination polyhedron of the copper atom is intermediate between the square and tetrahedron; the average distances are Cu-O 1.91 and Cu-N 1.95 , the O-Cu-O and N-Cu-N trans bond angles are 145.5° and 150.3°, respectively. The O-Cu-N chelate angle is 94.6°. The calculated energies of van der Waals intermolecular interactions are compared with the thermogravimetric characteristics of the complex with ketoiminate and copper(II) ethylenediamine-bis-acetylacetonate.Original Russian Text Copyright © 2004 by I. A. Baidina, P. A Stabnikov, A. D. Vasiliev, S. A. Gromilov, and I. K. IgumenovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 706–712, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Using Pseudoperiodicity for Polycrystal XRD Determination of the General Structural Motif of Coordination Compounds

This review summarizes experience in polycrystal diffractogram analysis for 100 coordination compounds using the translation sublattice isolation technique. The most widespread cases are described, and the general strategy of analysis is proposed. Conditions for transition from a rhombohedral sublattice to cubic lattices with different centerings are discussed.     

Synthesis and Crystal Structure of N-Hydroxy-9-(3'',4''-methylene-dioxyphenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10-decahydroacridine in Aqueous Media

The title compound N-hydroxy-9-(3',4'-methylenedioxyphenyl)-1,8-dioxo-1 ,2,3,4,5,6,7,8,9,10-decahydroacridine (C20H19NO5, Mr = 353.36) is of orthorhombic, space group Pna21 with a = 14.6914(16), b = 8.8103(10), c = 12.6648(14) (A), Z = 4, V = 1639.3(3) (A)3, Dc = 1.432 g/cm3,μt(MoKα) = 0.103 mm-1, F(000) = 744, R = 0.0445 and wR = 0.1043 for 2172 observed reflections (I ＞ 2σ(Ⅰ)). X-ray analysis reveals that the pyridine and cyclohexane rings adopt boat and half-chair in the title molecule.     

Crystal structure of a new polymorphic modification of β-K2[Pd(NO3)4]

X-ray diffraction is applied to study a new crystalline modification of K₂[Pd(NO₃)₄]-β-K₂[Pd(NO₃)₄]. It is found that the phase is isostructural with Na₂[Pd(NO₃)₄] and Rb₂[Pd(NO₃)₄]. Square coordination of the Pd atom is formed by oxygen atoms of monodentately coordinated nitrate groups. Original Russian Text Copyright ? 2009 by S. P. Khranenko, I. A. Baidina, and S. A. Gromilov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 374–377, March–April, 2009.     

蒋锡夔研究员及其在物理有机化学和有机氟化学领域的成就

蒋锡夔研究员是我国物理有机化学和有机氟化学的主要奠基人。本文首先介绍蒋锡夔研究员的科学经历,然后介绍他在不同时期取得的代表性科学成就,主要包括有关四氟乙烯的亲电加成反应,氟橡胶研究,亲卤反应,自由基化学及有机分子的簇集与自卷等方面的研究。     

Pharmaceutical Chemistry Today—Changes,Problems, and Opportunities

Dissatisfaction with empirical methods, high expectations of the public, poorly harmonized international regulations, and rising costs have induced pharmaceutical research to search for new approaches. As a consequence, the medicinal chemist's professional activity is in a state of change. His synthetic strategy is being increasingly influenced by the reasoning of molecular biology. Novel classes of biologically active compounds demand the development of new synthetic methods beyond the scope of modern preparative organic chemistry: enzymes and microorganisms, cell cultures, and genetic engineering are harnessed to supply highly complex structures. Major efforts are devoted to the development of reliable structure-activity relationships to rationalize his work. Thus the field of medicinal chemistry stretches from physical and physical organic chemistry far into the realm of biosciences, and the interdisciplinary character of this research is rapidly increasing. The author endeavors to convey an impression of this complex subject with the aid of selected examples.     

Crystal and Molecular Structure of trans-[Pd(Bu2S)2(NO2)2]

Single crystals of the [PdL₂(NO₂)₂] complex were obtained for the first time, where L is di-n-butylsulfide. Single crystal and powder diffraction studies provided new data on the molecular and crystal structure of this compound.     

Crystal structure refinement for trans-[Pd(NO3)2(H2O)2]

Single crystals of trans-[Pd(NO₃)₂(H₂O)₂] were obtained, and the crystal structure of this complex, previously obtained for polycrystals, was refined. Crystal data (BRUKER X8APEX diffractometer): a = 4.9973(7) Å, b = 10.5982(14) Å, c = 11.7008(17) Å, V = 619.70(15) ų, space group Pbca, Z = 4, d _calc = 2.856 g/cm³. The structure is composed of neutral complexes with a trans configuration. The square plane environment of the Pd atom is formed by four oxygen atoms (Pd-O(NO₃) 1.999(5) Å, Pd-O(H₂O) 2.030(5) Å) and completed to a distorted bipyramid by two intramolecular contacts (Pd…O(NO₃) 2.926 Å). The shortest hydrogen bonds are O…H 2.72 Å.     

Bis{2‐[(phenylimino)ethyl]‐1H‐pyrrol‐1‐ido‐κ2N,N′}nickel(II): a supramolecular structure formed by C—H...π hydrogen bonds

In the title compound, [Ni(C₁₂H₁₁N₂)₂], the Ni^II cation lies on an inversion centre and has a square‐planar coordination geometry. This transition metal complex is composed of two deprotonated N,N′‐bidentate 2‐[(phenylimino)ethyl]‐1H‐pyrrol‐1‐ide ligands around a central Ni^II cation, with the pyrrolide rings and imine groups lying trans to each other. The Ni—N bond lengths range from 1.894 (3) to 1.939 (2) Å and the bite angle is 83.13 (11)°. The Ni—N(pyrrolide) bond is substantially shorter than the Ni—N(imino) bond. The planes of the phenyl rings make a dihedral angle of 78.79 (9)° with respect to the central NiN₄ plane. The molecules are linked into simple chains by an intermolecular C—H...π interaction involving a phenyl β‐C atom as donor. Intramolecular C—H...π interactions are also present.     

Uranium-sulfilimine chemistry. The preparation of Cp2*UCl2(HNSPh2) and its hydrolysis with HNSPh2 · H2O

The reaction of Cp₂*UCl₂ with HNSPh₂ produces Cp₂*UCl₂(HNSPh₂), which is the first structurally characterized complex of a sulfilimine. The hydrolysis of Cp₂*UCl₂(HNSPh₂) with HNSPh₂ · H₂O yields a tetrauranium cluster whose heavy atom structure has been determined by x-ray diffraction and which is formulated as a U^IV/U^V complex: [Cp*(Cl)(HNSPh₂)U(μ₃-O)(μ₂-O)₂U(Cl)(HNSPh₂)₂]₂.     

Synthesis and Crystal Structure of N-Hydroxy-9-(3’,4’-methylene- dioxyphenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9, 10-decahydroacridine in Aqueous Media

1 INTRODUCTION Acridine derivatives are described to have many applications, such as biological fluorescent probes[1] as well as anti-tumor[2], anti-bacterial[3], anti-HIV[4] and anti-malarial[5] agents. Because of the importance of acridine derivatives, much work has been done for several decades. Among them the classical synthetic methods involve condensing functionalized anilines and o-halogeno- benzoic acid derivatives as well as several other steps resulting in the desired acridine[…     

Digitalis Research in Berlin–Buch—Retrospective and Perspective Views

“The following remarks consist partially of matter of fact, and partially of opinion. The former will be permanent; the latter must vary with the detection of error, or the improvement of knowledge. I hazard them with diffidence, and hope they will be examined with candour.” These declarations, which stem from the famous book “An Account of the Foxglove and some of its Medical Uses” by physician William Withering in 1785 in which he introduced preparations from digitalis leaves in the therapy of dropsy (cardiac failure), are cited here by the senior author because of his awareness of the difficulties in presenting a balanced report on his life-long research project on the further development of digitalis. His decision to devote himself to digitalis research originated at the bedside, when as a physician he experienced the grim final stages of cardiac failure in which no real help for the patients is possible. Unfortunately, his research project did not fit into the research program decreed by the Ministry of Science of the German Democratic Republic, so that he was ordered to stop the digitalis project in favor of biomembrane studies. Fortunately, he got round the ban simply by labeling the digitalis-like acting steroids as probes for the cell membrane-located Na⁺/K⁺-transporting ATPase which he had just recognized as the digitalis target (receptor) enzyme. These and other ventures by the authors are collated here for the first time. The aim of this review is to foster straightforward research for solving a major challenge: the development of steroidal drugs for the prevention and cure of cardiac failure.