Trapping an Elusive Phosphanyl-Phosphaalumene.

We describe our efforts to access a compound with an Al=P double bond by reaction of Al(Nacnac) towards [H2CN(Dipp)]2P(PCO) (Nacnac=HC[C(Me)N(Dipp)]2; Dipp=2,6-iPr2C6H3). Our observations are consistent with the formation of a transient phosphanyl-phosphaalumene at low temperatures (-70 °C), however this species was found to readily undergo intramolecular C-H activation of the ß-diketiminato ligand upon warming to room temperature. The reactivity of the transient complex toward small molecules including dihydrogen, carbon dioxide, phosphaketenes, amines and silanes could be explored at low temperatures, showcasing that the target compound can react as both a frustrated Lewis pair (via the pendant phosphanyl moiety) or in hydroelementation reactions of the Al=P bond. The elusive target molecule could be trapped by addition of a Lewis base (tetrahydrofuran) affording an isolable molecular species that reacts in an analogous fashion to the base-free compound.

Iminoboranes With Parent B=NH Entity: Imino Group Metathesis, Nucleophilic Reactivity and N-N Coupling.

While R2 C=N-R double bonds in organic imines are well established, the related iminoboranes R-B=N-R are either prone to oligomerization or can only be stabilized at sufficient steric congestion. In particular, the examples of unsubstituted parent B=N-H entity are rare. We demonstrate that the amino imidazoline-2-imine ligand system (HAmIm) not only gives rise to the isolation of a parent (AmIm)B=N-H iminoborane, but also to species of type (AmIm)B=N-SiMe3 with concomitant stabilization by lithium bromide. The double bond character in these systems is unambiguously corroborated by DFT calculations. The steric accessibility of the (AmIm)B=NH unit allows facile reactivity including metathesis reactions with C=O and C=S bonds, nucleophilic addition toward organic and organometallic carbonyl compounds, but also oxidative N-N coupling within a dimeric unit. Thus, the chemical behavior of the (AmIm)B=N-H and (AmIm)B=N-SiMe3 is distinctly different from that of organic imines.

Reductive Al-B σ-Bond Formation in Alumaboranes: Facile Scission of Polar Multiple Bonds.

We present facile access to an alumaborane species with electron precise Al-B σ-bond. The reductive rearrangement of 1-(AlI2 ), 8-(BMes2 ) naphthalene (Mes=2,4,6-Me3 C6 H2 ) affords the alumaborane species cyclo-(1,8-C10 H6 )-[1-Al(Mes)(OEt2 )-8-B(Mes)] with a covalent Al-B σ-bond. The Al-B σ-bond performs the reductive scission of multiple bonds: S=C(NiPrCMe)2 affords the naphthalene bridged motif B-S-Al(NHC), NHC=N-heterocyclic carbene, while O=CPh2 is deoxygenated to afford an B-O-Al bridged species with incorporation of the remaining ≡CPh2 fragment into the naphthalene scaffold. The reaction with isonitrile Xyl-N≡C (Xyl=2,6-Me2 C6 H4 ) proceeds via a proposed (amino boryl) carbene species; which adds a second equivalent of isonitrile to ultimately form the Al-N-B bridged species cyclo-(1,8-C10 H6 )-[1-Al(Mes)-N(Xyl)-8-B{C(Mes)=C-N-Xyl}] with complete scission of the C≡N triple bond. The latter reaction is supported with isolated intermediates and by DFT calculations.

Reactions of a Four-Membered Borete with Carbon, Silicon, and Gallium Donor Ligands: Fused and Spiro-Type Boracycles.

Donor-acceptor cyclopropanes or cyclobutanes are dipolar reagents, which are widely used in the synthesis of complex organic (hetero)cycles in ring expansion reactions. Applying this concept to boron containing heterocycles, the four-membered borete cyclo-iPr2 N-BC10 H6 reacted with the carbon donor ligands 2,6-xylylisonitrile and the carbene IMes :C(NMesCH)2 with ring expansion and ring fusion, respectively. In particular, the tetracyclic structure formed with IMes displays zwitterionic character and absorption in the visible region. In contrast to the carbene IMes, the heavier carbenoids :Si(NDippCH)2 and :Ga(AmIm) with a two-coordinate donor atom afford spiro-type bicyclic compounds, which display four-coordinate geometry at silicon or gallium. (TD-)DFT calculations provide deeper insight into the mechanism of formation and the absorption properties of these new compounds.

Correction: "Give me five"- an amino imidazoline-2-imine ligand stabilises the first neutral five-membered cyclic triel(i) carbenoids.

Correction for '"Give me five"- an amino imidazoline-2-imine ligand stabilises the first neutral five-membered cyclic triel(i) carbenoides' by Lars Denker et al., Chem. Commun., 2021, 57, 2816-2819, DOI: .

"Give me five" - an amino imidazoline-2-imine ligand stabilises the first neutral five-membered cyclic triel(I) carbenoides.

We present the first cyclic five-membered triel(i) carbenoides E(AmIm) for E = Ga, In, Tl; AmIm = amido imidazoline-2-imine, which fill the current gap between four- and six-membered triel(i) carbenoides supported by HGiso and HNacNac. Ga(AmIm) can act as a strong σ-donor ligand in transition metal complexes, while the intermediacy of the Al(i) carbenoide Al(AmIm) is rationalised based on the isolation of an Al(iii) insertion product.

Superseding ß-Diketiminato Ligands: An Amido Imidazoline-2-Imine Ligand Stabilizes the Exhaustive Series of B=X Boranes (X=O, S, Se, Te).

Boron reluctantly forms B=X (X=O, S, Se, Te) moieties, which has stimulated the quest for such species in the past few years. Based on the N,N'-chelating ß-diketiminato ligand (HNacNac), a new amido imidazoline-2-imine ligand system (HAmIm) is presented, giving rise to the isolation of an exhaustive series of Lewis acid free, monomeric chalcogen B=X boranes with documented π-bond character between boron and the chalcogen. The chalcogenoboranes are isoelectronic and isolobal to the respective ketones. The chemical behavior of the oxoborane (B=O) strongly resembles the classical carbonyl reactivity in C=O bonds. The improved stability provided by HAmIm arises from the formation of more-stable five-membered boron chelates versus the six-membered NacNac analogues and from the imidazoline-2-imine moiety providing enhanced σ- and π-donation. The HAmIm ligand class may supersede the widely employed NacNac system in certain applications.

Two π-Electrons Make the Difference: From BODIPY to BODIIM Switchable Fluorescent Dyes.

(aza-)BODIPY dyes (boron dipyrromethene dyes) are well-established fluorophores due to their large quantum yields, stability, and diversity, which led to promising applications including imaging techniques, sensors, organic (opto)electronic materials, or biomedical applications. Although the control of the optical properties in (aza-)BODIPY dyes by peripheral functional groups is well studied, we herein present a novel approach to modify the 12 π-electron core of the dipyrromethene scaffold. The replacement of two carbon atoms in the ß-position of a BODIPY dye by two nitrogen atoms afforded a 14 π-electron system, which was termed BODIIM (boron diimidazolylmethene) in systematic analogy to the BODIPY dyes. Remarkably, the BODIIM dye was obtained with a BH2 -rigidifying entity, which is currently elusive and highly sought after for the BODIPY dye class. DFT-Calculations confirm the [12+2] π-electron relationship between BODIPY and BODIIM and reveal a strong shape correlation between LUMO in the BODIPY and the HOMO of the BODIIM. The modification of the π-system leads to a dramatic shift of the optical properties, of which the fluorescent emission is most noteworthy and occurs at much larger Stokes shift, that is, ≈500 cm-1 in BODIPY versus >4170 cm-1 in BODIIM system in all solvents investigated. Nucleophilic reactivity was found at the meso-carbon atom in the formation of stable borane adducts with a significant shift of the fluorescent emission, and this behavior contrasts the reactivity of conventional BODIPY systems. In addition, the reverse decomplexation of the borane adducts was demonstrated in reactions with a representative N-heterocyclic carbene to retain the strongly fluorescent BODIIM compound, which suggests applications as fully reversible fluorescent switch.

Benzyl Borane NHC Adducts: Beyond B-C Bond Scission.

Benzyl-substituted boronates and borates are widely employed as mild sources in radical or anionic transfer reactions of benzyl entities. In this process the B-C bond to the benzyl moiety is essentially ruptured. In contrast, reactions with retention of the B-C bond are poorly investigated although several other reactive sites in benzyl-boron systems are clearly inherent. In this respect, the novel reactivity of the representative borane adduct IiPr-BH2 Bn [IiPr=:C{N(iPr)CH}2 , Bn=CH2 C6 H5 ] is demonstrated. Dihalogenation of the BH2 entity is observed with BCl3 and BBr3 , whereas BI3 either affords IiPr-BHI2 or proceeds with borylation of the aromatic phenyl ring to give a hydride-bridged bisborylated species. The photochemical mono- and dihalogenation of the benzylic CH2 group was demonstrated with elemental bromine Br2 . The brominated product IiPr-BBr2 -CHBr-C6 H5 was borylated at the benzylic carbon atom in an umpolung event with BI3 to afford the zwitterion IiPr-BI-CH(BI3 )-C6 H5 .

N-Heterocyclic Carbene Adducts of Alkynyl Functionalized 1,3,2-Dithioborolanes.

Alkynyl functionalized boron compounds are versatile intermediates in the areas of medicinal chemistry, materials science, and optical materials. In particular, alkynyl boronate esters [R1-C≡C-B(OR2)2] are of interest since they provide reactivity at both the alkyne entity, with retention of the B-C bond or alkyne transfer to electrophilic substrates with scission of the latter. The boron atom is commonly well stabilized due to (i) the extraordinary strength of two B-O bonds, and (ii) the chelate effect exerted by a bifunctional alcohol. We reasoned that the replacement of a B-O for a B-S bond would lead to higher reactivity and post-functionalization in the resulting alkynyl boronate thioesters [R1-C≡C-B(S2X)]. Access to this poorly investigated class of compounds starts form chloro dithioborolane cyclo-Cl-B(S2C2H4) as a representative example. Whereas syntheses of three coordinate alkynyl boronate thioesters [R1-C≡C-B(S2X)] proved to be ineffective, the reactions of NHC-adducts (NHC = N-heterocyclic carbene) of cyclo-Cl-B(S2C2H4) afforded the alkyne substituted thioboronate esters in good yield. The products NHC-B(S2C2H4)(C≡C-R1) are remarkably stable towards water and air, which suggests their use as boron-based building blocks for applications akin to oxygen-based boronate esters.

[DNVF-Memorandum III - Methods for Health Services Research, Part 4 - Concept and Methods for Organizational Health Services Research: Short Version]. / DNVF-Memorandum III ­ Methoden für die Versorgungsforschung, Teil 4 ­ Konzept und Methoden der organisationsbezogenen Versorgungsforschung: Kurzfassung.

Organizational health services research in Germany is of increasing relevance. Based on the guide on methods for organizational health services research of the Memorandum III, part 1 from the year 2009, the fundamentals and standards have now been refined. The memorandum captures the theoretical framework, basic methodological approaches and methods in health services research for the design, evaluation and implementation of complex interventions in healthcare organizations.

[DNVF-Memorandum III - Methods For Health Services Research, Part 4 - Concept and Methods For Organizational Health Services Research. Chapter 1 - Definition and Concept of Organizational Health Services Research]. / DNVF-Memorandum III ­ Methoden für die Versorgungsforschung, Teil 4 ­ Konzept und Methoden der organisationsbezogenen Versorgungsforschung. Kapitel 1 ­ Definition und Konzept der organisationsbezogenen Versorgungsforschung.

Organizational health services research is still a relatively young field of research in Germany which is of increasing interest. The German Network Health Services Research e.V. (DNVF e.V.) published in 2009 - supported by expert associations and individual members of the DNVF - a guide on "Methods for organizational health services research" of the Memorandum III, part 1[1]. Originating from this publication and facilitated by the increasing relevance of the field, a necessity to refine the conceptual and methodological basis became evident. The update and extension of the publication from 2009 consists of three chapters: (1) Definition and concept of organizational health services research, (2) Methodological approaches in organizational health services research: indicators, data sources, data collection and data analysis, (3) Methodological approaches for the design, evaluation and implementation of complex interventions in health care organizations. The aim of the first chapter is to present the theoretical framing and the definition of terms and tasks within organizational health services research.

[DNVF-Memorandum III - Methods for Health Services Research, Part 4 - Concept and Methods for Organizational Health Services Research. Chapter 2 - Methodological Approaches for Organizational Health Services Research: Measures, Data Sources, Data Collection and Data Analysis]. / DNVF-Memorandum III ­ Methoden für die Versorgungsforschung, Teil 4 ­ Konzept und Methoden der organisationsbezogenen Versorgungsforschung. Kapitel 2 ­ Methodische Ansätze der organisationsbezogenen Versorgungsforschung: Zielgrößen, Datenquellen, Datenerhebung und Datenanalyse.

Organizational health services research is still a relatively young field of research in Germany which is of increasing interest. The German Network Health Services Research e.V. (DNVF e.V.) published in 2009 - supported by expert associations and individual members of the DNVF - a guide on "Methods for organizational health services research" of the Memorandum III, part 1 1. Originating from this publication and facilitated by the increasing relevance of the field, a necessity to refine the conceptual and methodological basis became evident. The update and extension of the publication from 2009 consists of 3 chapters: (1) Definition and concept of organizational health services research, (2) Methodological approaches in organizational health services research: indicators, data sources, data collection and data analysis, (3) Methodological approaches for the design, evaluation and implementation of complex interventions in healthcare organizations. The aim of the second chapter is to derive methodological requirements and characteristics of organizational health services research - based on the unique characteristics of the research field presented in chapter 1.

The Lower Saxony research network design of environments for ageing: towards interdisciplinary research on information and communication technologies in ageing societies.

Worldwide, ageing societies are bringing challenges for independent living and healthcare. Health-enabling technologies for pervasive healthcare and sensor-enhanced health information systems offer new opportunities for care. In order to identify, implement and assess such new information and communication technologies (ICT) the 'Lower Saxony Research Network Design of Environments for Ageing' (GAL) has been launched in 2008 as interdisciplinary research project. In this publication, we inform about the goals and structure of GAL, including first outcomes, as well as to discuss the potentials and possible barriers of such highly interdisciplinary research projects in the field of health-enabling technologies for pervasive healthcare. Although GAL's high interdisciplinarity at the beginning slowed down the speed of research progress, we can now work on problems, which can hardly be solved by one or few disciplines alone. Interdisciplinary research projects on ICT in ageing societies are needed and recommended.