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International audience; The syntheses of the racemic amino alcohol racN(CH2CMe2OH)(CMe2CH2OH)(CH2CHMeOH) (L22'1*H3, 2) and its representative N(CH2CMe2OH)(CMe2CH2OH)(CH2C-(R)HMeOH) (L22'1RH3, 3) with the stereogenic carbon center being R-configured are reported. Also reported are the stannatranes L22'1*SnOt-Bu (4) L22'1RSnOt-Bu (6) and germatranes L22'1*GeOEt (5) and L22'1RGeOEt (7) as well as the trinuclear tin oxocluster [(mu 3-O)(mu 3-O-t-Bu){SnL22'1R}3] (8). NMR and IR spectroscopy, electrospray ionization mass spectrometry (ESI MS), and single crystal X-ray diffraction analysis characterize these compounds. Computational studies accompany the experimental work and help understand the diastereoselectivity observed in the course of the metallatrane syntheses.

A series of novel non-symmetric neutral N,N′,O-chelating ligands derived from the α-iminopyridine 2-(C(R1)[double bond, length as m-dash]N(C6H3-2,6-iPr2))-6-(R2R3P[double bond, length as m-dash]O)C5H3N (L1: R1 = H, R2 = R3 = Ph; L2: R1 = Me, R2 = R3 = Ph; L3: R1 = H; R2 = Ph, R3 = EtO; L4: R1 = Me, R2 = Ph, R3 = EtO; L5: R1 = H, R2 = R3 = iPrO; L6: R1 = Me, R2 = R3 = iPrO) were synthesized. Ligands L1–6 were reacted with SnCl2 and Sn(OTf)2 with the aim of studying the influence of different R2R3P[double bond, length as m-dash]O functional groups on the Lewis base mediated ionization of SnCl2 and Sn(OTf)2. While all ligands L1–6 provided the corresponding ionic tin(II) complexes [L1–6 → SnCl]+[SnCl3]− (1–6), only ligands L1, L4 and L6 were able to stabilize tin(II) dications [L1,4,6 → Sn(H2O)][OTf]2 (7–9). The auto-ionized compounds [L3–6 → SnCl]+[SnCl3]− possessing ethylphenyl phosphinate and diisopropylphosphite substituents undergo elimination of EtCl and iPrCl, respectively, yielding compounds 10–13. Thesecan either be interpreted as neutral tin(II)phosphinate chloride (10, 11) and tin(II)phosphonate chloride (12, 13), respectively, containing Sn–O and Sn–Cl bonds, and a P[double bond, length as m-dash]O → SnCl2 interaction, or as zwitterionic compounds, where the positive charge of the central tin atom is compensated by an [OSnCl2]− anion. Finally, DFT studies were performed to better understand the steric and electronic properties of the ligands L1–6 as well as the nature of the bonds in the resulting products, with a particular focus on complexes 10–13.

Purpose Radiolabelled somatostatin analogues targeting somatostatin receptors (SSR) are well established for combined positron emission tomography/computer tomography (PET/CT) imaging of neuroendocrine tumours (NET). [18F]SiTATE has recently been introduced showing high image quality, promising clinical performance and improved logistics compared to the clinical reference standard 68Ga-DOTA-TOC. Here we present the first dosimetry and optimal scan time analysis. Methods Eight NET patients received a [18F]SiTATE-PET/CT (250 ± 66 MBq) with repeated emission scans (10, 30, 60, 120, 180 min after injection). Biodistribution in normal organs and SSR-positive tumour uptake were assessed. Dosimetry estimates for risk organs were determined using a combined linear-monoexponential model, and by applying 18F S-values and reference target masses for the ICRP89 adult male or female (OLINDA 2.0). Tumour-to-background ratios were compared quantitatively and visually between different scan times. Results After 1 h, normal organs showed similar tracer uptake with only negligible changes until 3 h post-injection. In contrast, tracer uptake by tumours increased progressively for almost all types of metastases, thus increasing tumour-to-background ratios over time. Dosimetry resulted in a total effective dose of 0.015 ± 0.004 mSv/MBq. Visual evaluation revealed no clinically relevant discrepancies between later scan times, but image quality was rated highest in 60 and 120 min images. Conclusion [18F]SiTATE-PET/CT in NET shows overall high tumour-to-background ratios from 60 to 180 min after injection and an effective dose comparable to 68Ga-labelled alternatives. For clinical use of [18F]SiTATE, the best compromise between image quality and tumour-to-background contrast is reached at 120 min, followed by 60 min after injection.

Here, we describe an extension of our silicon fluoride acceptor (SiFA) protocol for 18F-labeling of peptides that addresses challenges associated with preparing a clinical-grade (Tyr3)-octreotate (TATE) tracer for diagnosis of neuroendocrine tumors (NETs). After several iterations of protocol optimization (e.g., finding the optimal pH at which the isotopic exchange (IE) reaction produces high radiochemical yields (RCYs)), the SiFA technology achieved clinical applicability, as showcased by radiosynthesis of [18F]SiFAlin-TATE ([18F]SiTATE), the first SiFA peptide used in the clinical diagnosis of NETs. The TATE peptide binds to somatostatin receptors associated with NETs. Radiolabeled TATE derivatives are routinely applied in clinical oncological PET imaging. The (SiFA) 18F-labeling technology is based on the IE of a 19F atom for a radioactive 18F atom, a highly efficient labeling reaction under mild conditions. The 19F is part of a biomolecule bearing the SiFA building block, composed of a central silicon (Si) atom, a 19F atom connected to the Si atom, and two Si-bound tert-butyl groups. The IE proceeds through a penta-coordinate bipyramidal intermediate, followed by elimination of non-radioactive 19F, yielding the labeled compound in high RCYs at room temperature (22 °C). The simplicity and lack of side-product formation of this approach enable a one-step, kit-like preparation of structurally complex and unprotected radiopharmaceuticals. Compounds such as peptides used for tumor imaging in nuclear medicine can be 18F-labeled without the need for complex purification protocols. [18F]SiTATE can be synthesized within 30 min in preparative RCYs of 42%, radiochemical purity of >97% and high molar activity of 60 GBq/µmol.

The syntheses of the novel silicon-bridged tris(tetraorganotin) compounds MeSi(CH2SnPh2R)3 (2, R=Ph; 5, R=Me3SiCH2) and their halogen-substituted derivatives MeSi(CH2SnPh(3���n)In)3 (3, n=1; 4, n=2) and MeSi(CH2SnI2R)3 (6, R=Me3SiCH2) are reported. The reaction of compound 4 with di-t-butyltin oxide (t-Bu2SnO)3 gives the oktokaideka-nuclear (18-nuclear) molecular diorganotin oxide [MeSi(CH2SnPhO)3]6 (7) while the reaction of 6 with sodium hydroxide, NaOH, provides the trikonta-nuclear (30-nuclear) molecular diorganotin oxide [MeSi(CH2SnRO)3]10 (8, R=Me3SiCH2). Both 7 and 8 show belt-like ladder-type macrocyclic structures and are by far the biggest molecular diorganotin oxides reported to date. The compounds have been characterized by elemental analyses, electrospray mass spectrometry (ESI-MS), NMR spectroscopy, 1H DOSY NMR spectroscopy (7), IR spectroscopy (7, 8), and single-crystal X-ray diffraction analysis (2, 7, 8)., Angewandte Chemie International Edition;Vol. 59. 2020, Issue 52, pp 23892-23898

Introduction [18F]SiTATE (formerly known as [18F]SiFAlin-TATE) was recently introduced as a highly promising imaging agent for the diagnosis of well-differentiated neuroendocrine tumors (NET) using positron emission tomography/computed tomography (PET/CT). A high tumor uptake and excellent image quality, the straightforward labeling approach, as well as the economic and logistic advantages of 18F- over 68Ga-labeled compounds predestinate [18F]SiTATE to become a potential new clinical reference standard. A novel state-of-the-art methodology of automated radiopharmaceutical production is required to establish [18F]SiTATE in clinical routine. This work illustrates the development of a novel synthesis procedure of [18F]SiTATE on an automated synthesis unit (ASU) and the clinical applicability of the tracer in human NET imaging. Methods A new synthesis protocol was generated for the production of [18F]SiTATE on the Scintomics GRP™ platform for clinical NET imaging. The synthesis was carried out according to common Good Manufacturing Practice (GMP) guidelines including all quality control measurements. To confirm utility, clinical batches (n = 3) were produced and applied to six patients diagnosed with NET. Results [18F]SiTATE was obtained in 54 ± 4% (n = 3) non-decay corrected radiochemical yield (RCY), with a radiochemical purity of 96.3 ± 0.1% and a molar activity (Am) of 472 ± 45 GBq/μmol (n = 3). Quality control measurements always met the local release criteria. All specifications were taken or adapted from the Ph.Eur. regulations. PET/CT imaging with [18F]SiTATE produced on the GRP™ module confirmed the expected high image quality. The in vivo distribution pattern and excellent tumor to non-tumor contrast observed, matched the quality of the manually prepared [18F]SiTATE batches. Conclusions The automated manufacture of [18F]SiTATE was developed using the Scintomics GRP™ platform. The high quality of the radiotracer matched stringent quality control requirements adhering to common GMP guidelines, and its clinical applicability was confirmed by human PET/CT investigations. Advances in knowledge and implications for patient care The automated process for the manufacture of [18F]SiTATE described herein represents an important contribution to make [18F]SiTATE routinely accessible for its use in clinical NET diagnosis.

Purpose Somatostatin analogues (SSA) are frequently used in the treatment of neuroendocrine tumours. Recently, [18F]SiTATE entered the field of somatostatin receptor (SSR) positron emission tomography (PET)/ computed tomography (CT) imaging. The purpose of this study was to compare the SSR-expression of differentiated gastroentero-pancreatic neuroendocrine tumours (GEP-NET) measured by [18F]SiTATE-PET/CT in patients with and without previous treatment with long-acting SSAs to evaluate if SSA treatment needs to be paused prior to [18F]SiTATE-PET/CT. Methods 77 patients were examined with standardised [18F]SiTATE-PET/CT within clinical routine: 40 patients with long-acting SSAs up to 28 days prior to PET/CT examination and 37 patients without pre-treatment with SSAs. Maximum and mean standardized uptake values (SUVmax and SUVmean) of tumours and metastases (liver, lymphnode, mesenteric/peritoneal and bones) as well as representative background tissues (liver, spleen, adrenal gland, blood pool, small intestine, lung, bone) were measured, SUV ratios (SUVR) were calculated between tumours/metastases and liver, likewise between tumours/metastases and corresponding specific background, and compared between the two groups. Results SUVmean of liver (5.4 ± 1.5 vs. 6.8 ± 1.8) and spleen (17.5 ± 6.8 vs. 36.7 ± 10.3) were significantly lower (p < 0.001) and SUVmean of blood pool (1.7 ± 0.6 vs. 1.3 ± 0.3) was significantly higher (p < 0.001) in patients with SSA pre-treatment compared to patients without. No significant differences between tumour-to-liver and specific tumour-to-background SUVRs were observed between both groups (all p > 0.05). Conclusion In patients previously treated with SSAs, a significantly lower SSR expression ([18F]SiTATE uptake) in normal liver and spleen tissue was observed, as previously reported for 68Ga-labelled SSAs, without significant reduction of tumour-to-background contrast. Therefore, there is no evidence that SSA treatment needs to be paused prior to [18F]SiTATE-PET/CT.

The incorporation of silicon fluoride acceptor (SiFA) moieties into a variety of molecules, such as peptides, proteins and biologically relevant small molecules, has improved the generation of 18F-radiopharmaceuticals for medical imaging. The efficient isotopic exchange radiofluorination process, in combination with the enhanced [18F]SiFA in vivo stability, make it a suitable strategy for fluorine-18 incorporation. This review will highlight the clinical applicability of [18F]SiFA-labeled compounds and discuss the significant radiotracers currently in clinical use.

PET/CT using 68Ga-labeled somatostatin analogs (SSA) targeting somatostatin receptors (SSR) on the cell surface of well-differentiated neuroendocrine tumors (NET) represents the clinical reference standard for imaging. However, economic and logistic challenges of the 68Ge/68Ga generator-based approach have disadvantages over 18F-labeled compounds. Here, we present the first in-human data of 18F-SiFAlin-TATE, a novel 18F-labeled, SSR-targeting peptide. The aim was to compare the intra-individual biodistribution, tumor uptake, and image quality of 18F-SiFAlin-TATE to the clinical reference standard 68Ga-DOTA-TOC. Thirteen patients with NET staged with both 68Ga-DOTA-TOC and 18F-SiFAlin-TATE PET/CT have been included in this retrospective analysis. We compared the biodistribution in normal organs and tumor uptake of NET lesions by SUVmean and SUVmax measurement for tracers. Additionally mean and max tumor-to-liver (TLR) and tumor-to-spleen ratios (TSR) have been calculated by division of SUVmean and SUVmax of tumor lesions by the SUVmean of the liver and spleen, respectively. Additionally, image quality was visually rated by 5 blinded readers and an intra-class correlation (ICC) analysis on inter-observer agreement has been performed. Compared with 68Ga-DOTA-TOC, the biodistribution of 18F-SiFAlin-TATE showed somewhat higher, however, statistically not significant higher uptake in the liver, spleen, and adrenal glands. Significantly higher uptake was observed in the kidneys. Tumor uptake was higher in most tumor lesions with significantly higher uptake in common metastatic sites of NET including the liver (SUVmax 18.8 ± 8.4 vs. 12.8 ± 5.6; p

Four dinuclear organotin halides of composition XnPh(3–n)SnCH2Si(Me)2–C12H8–Si(Me)2CH2SnPh(3–n)Xn (X = Cl, I; n = 1, 2) were prepared and combined in 1:1 stoichiometric reactions with potassium 2,5...

The syntheses of the novel stannatranes N(CH2CMe2O)3Sn-(1S)-(−)-OC(O)C(OMe)(CF3)(C6H5), 1(S, Δ), and N(CH2CMe2O)3Sn-(1R)-(+)-OC(O)C(OMe)(CF3)(C6H5), 2(R, Λ), and germatranes N(CH2CMe2O)3Ge-(1S)-(−)-OC(O)C(OMe)(CF3)(C6H5), 3(S, Δ), and N(CH2CMe2O)3Ge-(1R)-(+)-OC(O)C(OMe)(CF3)(C6H5), 4(R, Λ) (with 1, S, Δ-configured/2, R, Λ-configured and 3, S, Δ-configured/4, R, Λ-configured being pairs of enantiomers) are reported. The compounds were characterized by NMR and IR spectroscopy, electrospray ionization mass spectrometry, and single crystal X-ray diffraction analysis. The epimerization via Λ ⇌ Δ ring flip of the enantiomeric stannatrane pair 1(S, Δ)/2(R, Λ) was investigated by NMR experiments at variable temperatures and density functional theory (DFT) calculations.

GlucoSiFA derivatives bearing an azide or alkynyl side chain were obtained from peracetyl-d-glucose using as key step a tosylate substitution by a SiFA thiolate obtained from 4-(di-tert-butylfluorsilyl)benzenethiol. In analogy, two-fold SiFA-substituted maltose and lactose derivatives were synthesized via bistosylates. Introduction of an ­acetal-protecting group in β-d-azidolactose allowed the synthesis of a LactoSiFA derivative bearing only one SiFA moiety.

PET using 68Ga-labeled somatostatin receptor (SSTR) ligands adds significant information in meningioma patients. 18F-SiTATE is a novel, 18F-labeled SSTR-targeting peptide with remarkable imaging properties. Here, we present a 72-year-old woman with falx meningioma and transosseous extension. 18F-SiTATE PET/CT was performed 12 months after the previous 68Ga-DOTATOC PET/CT with comparable quantitative uptake and very good spatial resolution. So far, the widespread use of SSTR ligands for NET and meningioma imaging is hampered by cost-intensive 68Ge/68Ga generators, low activity amounts, lower spatial resolution, and short half-life. 18F-SiTATE might foster widespread use of SSTR ligands, overcoming the shortcomings of 68Ga-labeled ligands.

Hydrolysis reactions of di‐ and trinuclear organotin halides yielded large novel cage compounds containing Sn−O−Sn bridges. The molecular structures of two octanuclear tetraorganodistannoxanes showing double‐ladder motifs, viz., [{Me3SiCH2(Cl)SnCH2YCH2Sn(OH)CH2SiMe3}2(μ‐O)2]2 [1, Y=p‐(Me)2SiC6H4‐C6H4Si(Me)2] and [{Me3SiCH2(I)SnCH2YCH2Sn(OH)CH2SiMe3}2(μ‐O)2]2 ⋅0.48 I2 [2⋅0.48 I2, Y=p‐(Me)2SiC6H4‐C6H4Si(Me)2], and the hexanuclear cage‐compound 1,3,6‐C6H3(p‐C6H4Si(Me)2CH2Sn(R)2OSn(R)2CH2Si(Me)2C6H4‐p)3C6H3‐1,3,6 (3, R=CH2SiMe3) are reported. Of these, the co‐crystal 2⋅0.48 I2 exhibits the largest spacing of 16.7 Å reported to date for distannoxane‐based double ladders. DFT calculations for the hexanuclear cage and a related octanuclear congener accompany the experimental work., In an alternative approach to metal‐containing cage assemblies, air‐stable di‐, tri‐ and tetranuclear organotin compounds were explored in a combined experimental and theoretical approach for the synthesis of hexa‐ and octanuclear metal cages based on halide‐oxide (hydrolysis) reactions at the metal centres. Among these, there are two novel bis(tetraorganodistannoxanes) showing double‐ladder‐type structures with record of head‐to‐toe dimensions. From this contribution, multiple options for future development in different directions arise.

The syntheses of the novel silicon‐bridged tris(tetraorganotin) compounds MeSi(CH2SnPh2R)3 (2, R=Ph; 5, R=Me3SiCH2) and their halogen‐substituted derivatives MeSi(CH2SnPh(3−n)In)3 (3, n=1; 4, n=2) and MeSi(CH2SnI2R)3 (6, R=Me3SiCH2) are reported. The reaction of compound 4 with di‐t‐butyltin oxide (t‐Bu2SnO)3 gives the oktokaideka‐nuclear (18‐nuclear) molecular diorganotin oxide [MeSi(CH2SnPhO)3]6 (7) while the reaction of 6 with sodium hydroxide, NaOH, provides the trikonta‐nuclear (30‐nuclear) molecular diorganotin oxide [MeSi(CH2SnRO)3]10 (8, R=Me3SiCH2). Both 7 and 8 show belt‐like ladder‐type macrocyclic structures and are by far the biggest molecular diorganotin oxides reported to date. The compounds have been characterized by elemental analyses, electrospray mass spectrometry (ESI‐MS), NMR spectroscopy, 1H DOSY NMR spectroscopy (7), IR spectroscopy (7, 8), and single‐crystal X‐ray diffraction analysis (2, 7, 8)., The first representatives of a new generation of large molecular diorganotin oxides showing Reuleaux triangle‐shaped (7) and heart‐formed (8) structures are reported. Based on simple syntheses of a great variety of precursor molecules, the concept holds enormous potential for future work in supramolecular chemistry involving main‐group elements and beyond.

[A new synthesis protocol was generated for the production of [[The automated manufacture of [The automated process for the manufacture of [

Here, we describe an extension of our silicon fluoride acceptor (SiFA) protocol for

Two Schiff bases, 4-[(2-hydroxynaphthalen-1-yl)methylidene]amino}-1,5,-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (APNA) and 4-[(2,3-Dihydroxybenzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (SBAP) derived from 4-aminoantipyrine are reported. The compounds were recrystallized in methanol and characterized using spectroscopic techniques (IR, NMR) and single-crystal X-ray diffraction analysis. The XRD structure shows that APNA and SBAP crystallize respectively in the orthorhombic and monoclinic crystal systems, space groups of Pna2(1) and C2/c, and both has Z = 8 in the unit cells. SBAP has all trans configuration around its central C=N double bond. It is stabilized by C18–H18?N2 and C7–H7?O3 intramolecular hydrogen bonds. The presence of distinctive bond length of N3–C12 in APNA and C=N (1451 cm?1) stretching vibration in the IR spectrum of SBAP are evidence that the Schiff bases formed. Additional hydroxyl group in SBAP raised the TPSA (146.478 Å2) more than APNA's (83.087 Å2) which had more aromatic ring (increased conjugation) and lesser number of hydroxyl group. The computed molecular descriptors of APNA and SBAP suggest that pyrazolones will have no pharmacokinetic challenge if developed as drug. © 2020 Elsevier Masson SAS National Science Foundation: OCI-1053575 This Work Used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number OCI-1053575.

The syntheses and structures of tert-butylaminomethyl(mesityl)phosphinic acid ethyl ester 2 and its zinc dichloride complex 3 are reported. In the solid state, both compounds are dimeric via hydrogen bridges. In the complex 3, the phosphinic acid ester 2 coordinates the zinc dichloride diastereoselectively.

The ferrocene derivative (η5 -Cp)Fe{η5 -C5 H3 -1-(ArNCH)-2-(CH2 NMe2 )} (1; Ar=2,6-iPr2 C6 H3 )) reacts diastereoselectively with LiR by carbolithiation and subsequent hydrolysis to give (η5 -Cp)Fe{η5 -C5 H3 -1-(ArHNCHR)-2-(CH2 NMe2 )} (3: R=tBu; 4: R=Ph; 5: R=Me) in high yields. For R=tBu, the organolithium derivative (η5 -Cp)Fe{η5 -C5 H3 -1-(ArLiNCHR)-2-(CH2 NMe2 )} (2) was isolated. Compound 2 reacts with GeCl2 ⋅dioxane and SnCl2 to give the metallylene amide chlorides (η5 -Cp)Fe{η5 -C5 H3 -1-(ArMNCHtBu)-2-(CH2 NMe2 )} 6 (M=GeCl) and 7 (M=SnCl), respectively, which each contain three stereogenic centers. The potential of 7 as a ligand in transition-metal chemistry is demonstrated by formation of its complex (η5 -Cp)Fe{η5 -C5 H3 -1-(ArMNCHtBu)-2-(CH2 NMe2 )} [9, M= Sn(Cl)W(CO)5 ]. Treatment of 3 with tert-butyllithium at room temperature causes an unprecedented carbon-carbon bond cleavage whereas under kinetic control, lithiation at the Cp-3 position takes place, which leads to the isolation of (η5 -Cp)Fe{η5 -C5 H3 -1-(ArHNCHtBu)-2-(CH2 NMe2 )-3-SiMe3 } (10).

Syntheses and molecular structures of the dimeric tin-platinum complex [LSnPtCl2 (SMe2 )]2 (2), the tin-platinum clusters [{LSnPtCl(SMe2 )}2 SnCl2 )] (3) and [(LSn)3 (PtCl2 )(PtClSnCl)(LSnOHCl)] (6) (L=MeN(CH2 CMe2 O- )2 ), and of the unprecedented tin(II) aminoalkoxide-tin oxide chloride complex [O(SnCl)2 ⋅(SnL)2 ] (5) are reported. The compounds were characterized by NMR spectroscopy (1 H, 13 C, 119 Sn, 195 Pt), 119 Sn Mossbauer spectroscopy (1-3, 6), electrospray ionization mass spectrometry, elemental analyses, and single-crystal X-ray diffraction analyses (2⋅CH2 Cl2 , 3⋅2 C4 H8 O, 5, 6⋅3CH2 Cl2 ). The tin(II) aminoalkoxide [MeN(CH2 CMe2 O)2 Sn]2 (1) behaves like a neutral ligand, inserts into a Pt-Cl bond, or is involved in rearrangement reactions with the different behavior occurring even within one compound (3, 6). DFT calculations show that the tin-platinum compounds behave like electronic chameleons.

The increased Lewis acidity in organotin-functionalized crown ethers X3SnCH2[19]-crown-6 (5, X = I; 6, X = Br; 7, X = Cl) not only resulted in ditopic complexation of sodium/potassium halides, but also offers an excellent strategy to manipulate through intramolecular O→Sn interactions the selectivity of the crown ether moiety towards Na+/K+ depending on the solvent.

The Schiff base 3-{( E )-[(2-hydroxyphenyl)imino]methyl}benzene-1,2-diol was synthesized by the condensation of 2,3-dihydroxybenzaldehyde and 2-aminophenol in water at room temperature. The crystal was grown using two solvents (dry methanol and 60% methanol). The compound was characterized using elemental microanalysis, IR, NMR, UV spectroscopies and single-crystal X-ray diffraction crystallography. The X-ray structure reveals that the Schiff base crystallizes as a methanol solvate in dry methanol with triclinic crystal system, space group P-1 and Z = 2 in the unit cell and as a non-methanol solvate in 60% methanol with triclinic crystal system, space group P-1 and Z = 4 in the unit cell. The compound showed absorption bands at 272, 389, 473 and 602 nm in DMSO. These bands were assigned as π → π ∗ , n → π ∗ and n-σ ∗ transitions. The 473 and 602 nm bands in DMSO reveal that the compound exists in tautomeric forms. The presence of N-H, C-O and C N stretching vibrations in the IR spectrum indicates that the compound is zwitterionic in the solid state. This study was supplemented using density functional theory method.

Two new bromine head-containing oxacalix[2]arene[2]triazines were designed and synthesized. Owing to the bromine head and complementary V-shaped cavity, the solid state structure of oxacalix[2]arene[2]triazine having N,N-dipropylamino substituents showed an intriguing and unique 1D-supramolecular chain-like self-assembly. To provide deep insight into the true nature of the observed stabilizing interactions, i.e., lone pair–π or σ-hole–π interactions, theoretical calculations were carried out. The computations confirm the presence of genuine σ-hole–π interactions. On the other hand, the calculations on the analogous oxacalix[2]arene[2]triazine having chlorine substituents revealed the greater π-acidic character of the s-triazine rings, thus proposing the cleft-like cavity to be more suitable for lone pair–π interactions. This is supported by retrieving the X-ray single crystal structure of the parent oxacalix[2]arene[2]triazine from the CSD which showed the existence of mixed lone pair–π/σ-hole–π and true lone pair–π interactions in the solid state. The study provides constructive clues on the utility of these macrocycles in host–guest and related fields of supramolecular chemistry.

Nanoparticles represent the most widely studied drug delivery systems targeting cancer. Polymeric nanoparticles can be easily generated through a microemulsion polymerization. Herein, the synthesis, radiolabeling, and in vivo evaluation of nanoparticles (NPs) functionalized by an organosilicon fluoride acceptor (SiFA) are reported which can be radiolabeled without further chemical modifications. Four nanoparticles in the sub-100 nm range with distinct hydrodynamic diameters of 20 nm (NP1), 33 nm (NP2), 45 nm (NP3), and 72 nm (NP4), respectively, were synthesized under size-controlled conditions. The SiFA-labeling building block acted as an initiator for the polymerization of polymer P1. The nanoparticles were radiolabeled with fluorine-18 (18F) through simple isotopic exchange (IE) and analyzed in vivo in a murine mammary tumor model (EMT6). The facile 18F radiolabeling SiFA methodology, performed in ethanol under mild reaction conditions, gave radiochemical yields (RCYs) of 19–26% and specific activities...

Two Schiff bases namely N,N′-Bis-[3-(4-metoxy-phenyl)-allylidene]ethane-1,2-diamine (TPMC/EDA) and [3-(4-methoxy-phenyl)-allylidene]-phenyl-amine (TPMC/AN) were synthesized. They were characterized using elemental microanalysis, IR, NMR, UV and mass spectroscopies. Single crystals of TPMC/AN were also analyzed by X-ray diffraction and the compound was examined using B3LYP/6–311++G(d,p) method. A Monoclinic crystal system and space groups of P21/c were obtained for the crystal. Docking calculations on the compounds showed they interacted with fungal N-myristoyltransferase and bacteria DNA gyrase at 2.62–2.95 and 190.26–98.99 μM ranges. The predicted docked poses identified unique binding modes of the compounds and vital intermolecular interactions. The anti-microbial screening of the compounds were carried out against Escherichia coli, Bacillus subtillis, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger using agar well diffusion method. The standard drugs used were the anti-bacterial ciprofloxacin and the anti-fungal fluconazole. The compounds showed activity against all the microorganisms comparable to the used standard drugs. TPMC/EDA was more active than the standard fungal drug in the screening against the fungi strain, Aspergillus niger. It showed the MIC and IZD of 1.3 mg/ml and 9.0 mm respectively. These suggest that the compounds are potential bactericidal and fungicidal candidates.

Six novel neutral organotin(IV) complexes, viz. [n-Bu2Sn(L4-PyAQ)2] 1, [Bz2Sn(L4-PyAQ)2] 2, [Ph2Sn(L4-PyAQ)2] 3, [Ph2Sn(L3-PyAQ)2] 4, [Bz3Sn(L4-PyAQ)] 5 and [Ph3Sn(L4-PyAQ)] 6 have been synthesized via reactions of 3/4-pyridyl-quinolin-8-ol pro-ligands, with appropriate diorganotin oxide and triorganotin hydroxide precursors, respectively. The compounds 1-6 were characterized in solution by means of NMR spectroscopy while the solid-state structures of 1, 6, and of the solvates 2·1.5C6H6, 3·0.25C6H6, 2·4·C6H6, and 5·0.5H2O were authenticated by single crystal X-ray diffraction analysis. In the solid-state, the tin centers in 1-2·4·C6H6 are hexacoordinated and reveal a distorted cis-octahedral environment. In 5·0.5H2O and 6, the tin centers are pentacoordinated and show a coordination environment between trigonal-bipyramidal and square pyramidal.

Herein, we report the syntheses of the novel P(O)(Oi-Pr)2- and organostannyl-substituted ferrocene derivatives Fe[{η5-C5H3-1-SnPh3-2-P(O)(Oi-Pr)2}{η5-C5H4P(O)(Oi-Pr)2}] (1a), Fe[η5-C5H3-1-SnPh3-2-P(O)(O-i-Pr)2]2 (1b), Fe[{η5-C5H2-1,3-(SnPh2X)2-2-P(O)(Oi-Pr)2}{η5-C5H4P(O)(Oi-Pr)2}] (2, X = I; 3, X = Br; 4, X = Cl; 5, X = F) and η5-CpFeη5-C5H-1,3-(SnPh3)2-4,5-[P(O)(Oi-Pr)2]2 (7). Furthermore, we report the synthesis of the organotin iodide η5-CpFeη5-C5H-1,3-(SnPh2I)2-4,5-[P(O)(Oi-Pr)2]2 (8), and its reactions with KF, AgPF6, I2 and AgClO4 providing the corresponding organotin derivatives η5-CpFeη5-C5H-1,3-(SnPh2I)2-4,5-[P(O)(Oi-Pr)2]2 (9), η5-CpFeη5-C5H-1,3-(SnPhI2)2-4,5-[P(O)(Oi-Pr)2]2 (10), and [η5-CpFeη5-(C5H-1-SnPh2OH-3-SnPh2-4,5-{P(O)(Oi-Pr)2}2)]ClO4∙H2O (11). The latter compound is the first example of an air stable, tetra-substituted ferrocene derivative containing a bicentric (bis)organotin cation. The compounds are characterized by elemental analyses, 1H, 13C, 31P, 119Sn NMR and IR spectroscopy, electrospray ionization mass spectrometry, and, except for 6 and 9, single crystal X-ray diffraction analyses.

The metallation of 1,3-diiodoferrocene (A) provides novel ferrocene-based D,C,D-containing (D = O, S) pincer type ligands η5-CpFeη5-C5H3-1,3-[P(D)R2]2 (1; D = O, R= OiPr, 2; D = O, R = OPh, 3; D = S, R = Ph). The corresponding organotin derivatives η5-CpFeη5-C5H2-1-SnPh3-2,5-[P(O)(O-i-Pr)2]2 (4), η5-CpFeη5-C5H2-1-SnPh2I-2,5-[P(O)(O-i-Pr)2]2 (5) and η5-CpFeη5-C5H2-1-SnMe3-2,4-[P(S)Ph2]2 (6) are reported as well. The compounds are characterized by elemental analyses, 1H, 13C, 31P, 119Sn NMR and IR spectroscopy, electrospray ionization mass spectrometry, and single crystal X-ray diffraction analyses (3 and 4).