Trigonal Bipyramidal Structure Research Articles

アピコフィリシティー則に反した５配位リン化合物の合成と性質

Since the synthesis of the first pentacoordinated organophosphorus compound, Ph5P, by Wittig, the chemistry of pentacoordinated phosphorus compounds has been extensively expanded. Pentacoordinated phosphorus compounds usually take a trigonal bipyramidal structure with two distinctive sites; apical and equatorial positions. In the trigonal bipyramidal structure, electronegative and small substituents prefer the apical positions. Such properties are widely recognized as the apicophilicity rule. However, several examples breaking the apicophilicity rule have been reported in the past few decades and novel properties and reactivities of these new classes of compounds have been found. In this review, the synthesis of novel pentacoordinated phosphoranes with anti-apicophilic arrangement will be introduced, as well as their structures, spectroscopic properties, and reactivities.

Preparation and Mechanism Study of Mesoporous Titania Whiskers

A simple novel procedure for the,synthesis of mesoporous titania whiskers from potassium dititanate(K_2Ti_2O_5)was reported.Nanostructure whisker was obtained via controlling mesostructure transition process of the unstable trigonal bipyramidal layered crystal structure of K_2Ti_2O_5 in a hydra- tion step.XRD,TEM and HREM results confirm the existence of nanophase KOH·nH_2O inside the inorganic framework.Removing of nanophase KOH.nH_2O by acid solution leads to the formation of mesoporous structure with the specific surface area up to 248m~2/g.The mesoporous structure of TiO_2 whiskers and fibrous morphology can be preserved by calcination at 500℃with the specific surface area of 139m~2/g and the pore diameter of 8.7nm.

H2O2-Reactivity of Copper(II) Complexes Supported by Tris[(pyridin-2-yl)methyl]amine Ligands with 6-Phenyl Substituents

The structure and H(2)O(2)-reactivity of a series of copper(II) complexes supported by tris[(pyridin-2-yl)methyl]amine (TPA) derivatives having a phenyl group at the 6-position of pyridine donor group(s) [(6-phenylpyridin-2-yl)methyl]bis[(pyridin-2-yl)methyl]amine (Ph(1)TPA), bis[(6-phenylpyridin-2-yl)methyl][(pyridin-2-yl)methyl]amine (Ph(2)TPA), and tris[(6-phenylpyridin-2-yl)methyl]amine (Ph(3)TPA) have systematically been examined to get insights into the aromatic substituent (6-Ph) effects on the coordination chemistry of TPA ligand system. The X-ray crystallographic analyses have revealed that [Cu(II)(TPA)(CH(3)CN)](ClO(4))(2) (CuTPA) and [Cu(II)(Ph(3)TPA)(CH(3)CN)](ClO(4))(2) (3) exhibit a trigonal bipyramidal structure, whereas [Cu(II)(Ph(1)TPA)(CH(3)CN)](ClO(4))(2) (1) shows a slightly distorted square pyramidal structure and [Cu(II)(Ph(2)TPA)(CH(3)CN)](ClO(4))(2) (2) has an intermediate structure between trigonal bipyramidal and square pyramidal. On the other hand, the UV-vis and ESR data have suggested that all the copper(II) complexes have a similar trigonal bipyramidal structure in solution. The redox potentials of CuTPA, 1, 2, and 3 have been determined as E(1/2) = -0.34, -0.28, -0.16, and -0.04 mV vs Ag/AgNO(3), respectively, demonstrating that introduction of each 6-Ph group causes positive shift of E(1/2) about 0.1 V. Notable difference in H(2)O(2)-reactivity has been found among the copper(II) complexes. Namely, CuTPA and 1 afforded mononuclear copper(II)-hydroperoxo complexes CuTPA-OOH and 1-OOH, respectively, whereas complex 2 provided bis(mu-oxo)dicopper(III) complex 2-oxo. On the other hand, copper(II) complex 3 was reduced to the corresponding copper(I) complex 3(red). On the basis of the H(2)O(2)-reactivity together with the X-ray structures and the redox potentials of the copper(II) complexes, the substituent effects of 6-Ph are discussed in detail.

Heteroborane analogs of silicon clusters: Experimental and theoretical studies on Bi2Si5 and Bi2Si5−

We have investigated the electronic structure of anionic and neutral Bi(2)Si(5) by means of anion photoelectron spectroscopy and density functional calculations. Both the experiments and calculations reveal that the Bi(2)Si(5)(-) anion prefers to adopt a distorted trigonal-bipyramidal structure with Bi(2) bridges. Following the isolobal analogy between divalent Si and B-H group, we show that both neutral Bi(2)Si(5) and neutral Bi(2)B(5)H(5) adopt similar pentagonal-bipyrmidal geometries and have analogous orbital energy patterns.

Synthesis, Crystal Structure, and Properties of a Novel Copper(II) Complex with the Tripod Ligand Tris(N-Methylbenzimidazol-2-ylmethyl)Amine and 2-Methacrylate

A novel five-coordinate copper complex with the tripod ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and 2-methacrylate, with the composition [Cu(Mentb)(2-methacrylate](ClO4)· 2DMF· 0.5H2O, was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and UV. The crystal structure of the copper complex has been determined by a single-crystal X-ray diffraction method, and shows that the CuII atom is bonded to a tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) ligand and a 2-methacrylate molecule through four N atoms and one O atom, giving a distorted trigonal-bipyramidal coordination geometry (τ = 0.78), with approximate C3 molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasireversible Cu+2/Cu+ couple. Electron spin resonance data confirm the trigonal-bipyramidal structure and indicate g‖ < g∞ with a very small value of A (23 × 10−4 cm−1).

A Biomimetic Approach to Oxidized Sites in the Xanthine Oxidoreductase Family: Synthesis and Stereochemistry of Tungsten(VI) Analogue Complexes

Two series of square pyramidal (SP) monodithiolene complexes, [M (VI)O 3- n S n (bdt)] (2-) and their silylated derivatives [M (VI)O 2- n S n (OSiR 3)(bdt)] (-) ( n = 0, M = Mo or W; n = 1, 2, M = W), synthesized in this and previous work, constitute the basic molecules in a biomimetic approach to structural analogues of the oxidized sites in the xanthine oxidoreductase enzyme family. Benzene-1,2-dithiolate (bdt) simulates native pyranopterindithiolene chelation in the basal plane, tungsten instead of the native metal molybdenum was employed in sulfido complexes to avoid autoreduction, and silylation models protonation. The complexes [MO 3(bdt)] (2-) and [MO 2(OSiR 3)(bdt)] (-) represent inactive sites, while [MO 2S(bdt)] (2-) and [MOS(OSiR 3)(bdt)] (-), with basal sulfido and silyloxo ligands, are the first analogues of the catalytic sites. Also prepared were [MOS 2(bdt)] (2-) and [MS 2(OSiR 3)(bdt)] (-), with basal sulfido and silyloxo ligands. Complexes are described by angular parameters which reveal occasional distortions from idealized SP toward a trigonal bipyramidal (TBP) structure arising from crystal packing forces in crystalline Et 4N (+) salts. Miminized energy structures from DFT calculations are uniformly SP and reproduce experimental structures. For example, the correct structure is predicted for [WO 2S(bdt)] (2-), whose basal and apical sulfido diastereomers are potentially interconvertible through a low-lying TBP transition state for pseudorotation. The lowest energy tautomer of the protonated form is calculated to be [WOS(OH)(bdt)] (-), with basal sulfido and hydroxo ligands. Computational and experimental structures indicate that protein sites adopt intrinsic coordination geometries rather than those dictated by protein structure and environment.

Pentanuclear and Heptanuclear Helicates By Self-Assembly of d10 Metal Ions and a Rigid Aromatic Bis-Bidentate Chelator

The self-assembly of Zn(II) and Cd(II) ions with a bis-bidentate ligand 3,5-bis(benzimidazol-2-yl)pyrazole (H 3L) was studied by Electrospray ionization mass spectrometry, (1)H NMR measurements, and single-crystal X-ray diffraction analyses. Reaction of Zn(ClO 4) 2.6H 2O and Cd(ClO 4) 2.6H 2O with H 3L in DMF gave two pentanuclear complexes [(Zn 5(mu 3-O)(H 2L) 6)(ClO 4) 2.DMF.9.5H 2O ( 1) and [Cd 5(mu 3-O)(H 2L) 6](ClO 4)(OH).4.75DMF.0.25EtOH.10.5H 2O ( 2), in which the trigonal-bipyramidal core structures are bridged by mu 3-oxo and pyrazolate rings of the monodeprotonated H 2L. When Na 3PO 4.12H 2O was used in the reaction system of CdBr 2.4H 2O and H 3L, [Cd 5(mu 3-O)(H 2L) 6]Br 2.4.5DMF.6.5H 2O ( 3) and [Cd 7(mu 6-PO 4)(mu-Br) 3(H 2L) 6](HPO 4).DMF.10H 2O ( 4) were isolated. 3 displays the same core structure as that of 2, whereas 4 exhibits a turbinate, heptanuclear core which is bridged by a mu 6-PO 4, three mu-Br, and three pyrazolate rings. All of the pentanuclear and heptanuclear cores are surrounded by three pairs of bis-bidentate H 2L (-) ligands with offset pi-pi stacking, showing propeller-like molecular structures and triple-stand helicates. Electrospray ionization mass spectrometry studies and (1)H NMR measurements demonstrate that the pentanuclear complexes have different stability in the solution, depending on the metal ions and the counteranions. Furthermore, both 1 and 2 emit blue fluorescence with nanosecond luminescent lifetimes in DMF at room temperature.

A pyrazine-bridged linear pentanuclear copper(II) complex and related tri- and dinuclear complexes showing various coordination structures and magnetic couplings

Sterically bulky pyrazines have been successfully utilized for the preparation of discrete oligo-nuclear TBP (trigonal bipyramidal), SqP (square pyramidal), and Oh (octahedral) copper(II) complexes. We have synthesized a unique linear pentanuclear complex [{Cu(hfac) 2} 5(μ-2-butyl-3-methylpyrazine) 4]. The two terminal copper(II) ions have a SqP structure while the three inner ions have an Oh one. The solvent molecule was incorporated in the clearance of the lattice. From another reaction under harsh conditions, we separated [{Cu(hfac) 2} 3(μ-2-butyl-3-methylpyrazine) 2], which can be regarded as the central moiety of the pentanuclear one. We also prepared a dinuclear complex [{Cu(hfac) 2} 2(μ-tetramethylpyrazine)], in which the pyrazine nitrogen atoms were located at TBP equatorial positions. Single-crystal EPR measurements supported its compressed TBP structure. The exchange coupling was antiferromagnetic with J TBP–TBP/ k B = −3.6 K. The linear trinuclear [{Cu(hfac) 2} 3(μ-2,3,5-trimethylpyrazine) 2], having two TBP Cu ions with an intervening Oh Cu ion, showed very weak antiferromagnetic coupling. DFT calculations on these compounds indicated that the σ-type orbital overlap between the Cu and N atoms is essential for superexchange interactions.

Synthesis and characterization of three new fluorovanadate complexes: N(C 2H 5) 4+[VOF 4] −, N(CH 3) 4+[VOF 3Cl] −, N(C 4H 9) 4+[VOF 3Br] − and theoretical calculations of VOF 4−, VOF 3Cl − and VOF 3Br − ions

The reaction of VOF 3 with (C 2H 5) 4NF, (CH 3) 4NCl and (C 4H 9) 4NBr salts in anhydrous CH 3CN produced new complexes with the anion general formula [VOF 3X] − in that (X = F −, Cl −, Br −). These were characterized by elemental analysis, IR, UV/Visible and 19F NMR spectroscopy. The optimized geometries and frequencies of the stationary point are calculated at the B3LYP/6-311G level of theory. Theoretical results showed that the V X (X = F, Cl, Br) bond length values for the [VOF 3X] − in compounds 1–3 are 1.8247, 2.4031 and 2.5595 Å, respectively. Also, the V F 5 bond length values in [VOF 3X] − are 1.824, 1.812 and 1.802 Å, respectively. These results reveal that the bond order for V X bonds decrease from compounds 1 to 3, while for V F 5 bonds, the bond orders increase. It can be concluded that the decrease of V X bonds lengths and the increase of V F 5 bond lengths in compounds 1–3 result from the increase of the hyperconjugation from compounds 1 to 3. Harmonic vibrational frequencies and infrared intensities for VOF 4 −, VOF 3Cl − and VOF 3Br − are studied by means of theoretical and experimental methods. The calculated frequencies are in reasonable agreement with the experiment values. These data can be used in models of phosphoryl transfer enzymes because vanadate can often bind to phosphoryl transfer enzymes to form a trigonal-bipyramidal structure at the active site.

Synthesis and Structure Characterization of Some Triorganotin Esters of Heteroaromatic Carboxylic Acid and Crystal Structure of Triphenyltin Esters of 6-Hydroxynicotinic Acid and 5-Chloro-6-hydroxynicotinic Acid

Reactions of (R3Sn)2O (R=Ph, 2-ClC6H4CH2, 2-FC6H4CH2, 4-CNC6H4CH2) with 6-hydroxynicotinic acid and 5-chloro-6-hydroxynicotinic acid in 1:2 stoichiometry yielded eight triorganotin compounds. These compounds have been characterized by elemental analysis, IR and 1H NMR spectroscopy. The crystal structures of triphenyltin esters of 6-hydroxynicotinic acid (1) and 5-chloro-6-hydroxynicotinic acid (2) were determined by single crystal X-ray diffraction. In these two compounds the tin atoms are rendered five-coordinate in a trigonal bipyramidal structure by coordination though the three phenyl carbon atoms and two oxygen atoms, one from carboxylate and other from the phenolic hydroxide. The resulting structures are two one-dimensional linear polymers through an interaction between the O atoms of phenolic hydroxide and tin atoms of an adjacent molecule.

Bonding of Seven Carbonyl Groups to a Single Metal Atom: Theoretical Study of M(CO)n (M = Ti, Zr, Hf; n = 7, 6, 5, 4)

The equilibrium geometries, thermochemistry, and vibrational frequencies of the homoleptic metal-carbonyls of the group 4 elements, M(CO)n (M = Ti, Zr, Hf; n = 7, 6, 5, 4) were predicted using density functional theory. Analogous M(CO)n structures were found for all three metals. The global minima for the 18-electron M(CO)7 molecules are all singlet C(3v) capped octahedra. The global minima for the 16-electron M(CO)6 species are triplet M(CO)6 structures distorted from O(h) symmetry to D(3d) symmetry. However, the corresponding singlet M(CO)6 structures lie within 5 kcal/mol of the triplet global minima. The global minima for M(CO)n (n = 5, 4) are triplet structures derived from the D(3d) distorted octahedral structures of M(CO)6 by removal of one or two CO groups, respectively. Quintet D(3h) trigonal bipyramidal structures for M(CO)5 and singlet T(d) tetrahedral structures for M(CO)4 are also found, as well as higher energy structures for M(CO)6 and M(CO)7 containing a unique CO group bonded to the metal atom through both M-C and M-O bonds. The dissociation energies M(CO)7 --> M(CO)6 + CO are substantial, indicating no fundamental problem in bonding seven CO groups to a single metal atom.

Synthesis, crystal structure and properties of a copper(II) complex with the tripod ligand tris ( N -methylbenzimidazol-2-ylmethyl)amine and 4-hydroxycinnamate

A five-coordinate copper complex with the tripod ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and 4-hydroxycinnamate, with the composition [Cu(Mentb)(4-hydroxycinnamate)](ClO4) · 0.5DMF, was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and UV. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the CuII atom is bonded to a tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) ligand and a 4-hydroxycinnamate through four N atoms and one O atom, giving a distorted trigonal-bipyramidal coordination geometry (τ = 0.78), with approximate C3 molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasireversible Cu+2/Cu+ couple. Electron spin resonance data confirm the trigonal–bipyramidal structure and indicate g ∥ < g ⊥ with a very small value of A ∥ (57 × 10−4 cm−1).

Interaction of dimethyltin(IV) dichloride with 5′‐IMP and 5′‐UMP

AbstractThe formation constants of the species formed in the systems H+ + dimethyltin(IV) + 5′‐IMP and 5′‐UMP, H+ + 5′‐IMP and H+ + 5′‐UMP have been determined in aqueous solution in the pH range 1.5–9.5 at constant temperature (25 °C) and constant ionic strength (0.1 mol dm−3 NaClO4), using spectrophotometric and potentiometric techniques. 1H and 31P NMR investigations in aqueous solution confirmed the species formation. The precipitated complexes of IMP and UMP by Me2Sn(IV)2+ at low pH values were characterized by elemental analysis and FTIR spectroscopy methods, the bonding sites of the ligands were determined and ruled out purine and pyrimidine moieties (N‐7 and N‐1 in IMP and N‐3 in UMP, respectively) while a bidentated coordination of the phosphate group is concluded in both cases. Finally, the experiments revealed the existence of complexes with trigonal bipyramidal structures that is in agreement with similar systems resulted previously. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Chemistry of Carbaphosphatranes

A 5-carbaphosphatrane and a 6-carbaphosphatrane were synthesized by utilizing triarylmethyl-type tetradentate ligands. Their structures were determined by X-ray crystallographic analysis to reveal that they have nealy ideal trigonal bipyramidal structures with a perfectly anti-apicophilic arrangement. 1 J PH and 1 J PC values of carbaphosphatranes were shown to be extraordinarily large as an apical coupling constant. The reactivities of carbaphosphatranes based on the tautomerization with their corresponding phosphonites were demonstrated in some reactions.

Dynamics and magnetic resonance properties of Sc3C2@C80 and its monoanion

We report density functional theory (DFT) studies on the endohedral scandium carbide fullerene Sc3C2@C80 and its monoanion [Sc3C2@C80](-). The system consisting of a Sc3C2 moiety inside the Ih C80 fullerene has been studied by using first principles molecular dynamics simulations at the DFT level. On the picosecond time scale, the triangle defined by the scandium atoms is seen to jump between orientations along the equatorial six-membered ring belt of the cage. The confined carbide unit, in turn, is engaged in a flipping motion through the Sc3 plane. In contrast to the equilibrium geometry optimisations using large basis sets that predict a trigonal bipyramidal structure, a planar Sc3C2-moiety is preferred during the finite-temperature simulation. In the molecular dynamics picture, Sc3C2@C80 is best described as an equilibrium between the two static minimum structures. Calculations of the vibrational frequencies show that the earlier predicted C2 and C2v symmetric isomers are in fact saddle points, with one imaginary normal mode frequency that is related to the flipping motion of the confined carbon dimer. Reoptimisation revealed two new minimum energy structures where the C2 unit is tilted with respect to its orientation in the earlier suggested higher-symmetry structures. The nature of the bonding in the static structures of the two isomers of Sc3C2@C80 has been investigated using the electron localisation function and natural population analysis. Some increased electron pair localisation is detected on the six-membered rings closest to the Sc atoms. 13C nuclear magnetic resonance (NMR) chemical shifts have been calculated for the closed-shell monoanion of Sc3C2@C80. The 13C shifts were also calculated for Sc2C2@C84, for further comparison to experimentally measured spectra. The confined carbon atoms are strongly deshielded in these metallofullerenes, implying an incorrect earlier interpretation of the experimental 13C NMR spectrum of Sc2C2@C84. The neutral Sc3C2@C80 system with one unpaired electron is further characterised by calculating the hyperfine coupling constants, the g tensor, as well as paramagnetic NMR (pNMR) 13C shifts for both static isomers. The chemical shifts of the confined carbon atoms and the hyperfine coupling constants of all the confined atoms are strongly dependent on the conformation of the Sc3C2 moiety. Consequently, dynamical effects are expected to be important in the modelling of the magnetic properties of endohedral scandium carbide fullerenes. The two low-lying isomers have rather different pNMR 13C shifts, implying the potential of this method in structural assignment.

Ab initio calculations of complexes of tetrachlorides of Group IVA elements: VIII. Structure of SiCl4 complexes with hexamethylphosphoric triamide and dynamics of their formation

Quantum-chemical calculations of the systems SiCl4←OP[N(CH3)2]3 and SiCl4←2OP[N(CH3)2]3 with complete optimization of their geometry at various Si←O distances were performed by the RHF/6-31G(d) method. The first system was also calculated by the MP2/6-31G(d) method. The calculations of the systems with the complete geometry optimization resulted in trigonal-bipyramidal and trans-octahedral structures, respectively, having energy minima. When the components of the latter system approach each other, first their mutual polarization occurs, and then it is accompanied by electron density transfer from the H and P atoms of the electron-donor molecules to the Cl atoms of the acceptor. The results of the calculation of the trans-octahedral complex agree with the experimental 35Cl NQR data. The electron density of Cl atoms increases upon complex formation, mainly due to an increase in their pσ electron density.

THE TEMPERATURE DEPENDENCE OF THE ELECTRICAL CONDUCTIVITY OF DIAZADIPHOSPHETIDINE DERIVATIVES

The d.c. electrical conductivity measurements as a function of temperature of 2,2,2,4,4,4­hexachloro-1,3 bis(2-chlorophenyl)-1,3,2,4-diazadiphosphetidine, (HCCIDP),2,2,2,4,4,4­-hexachloro-1,3-bis(2-bromophenyl)-1,3,2,4-diazadiphosphetidine (HCBrDP), and 2,2,2,4,4,4­-hexachloro-1,3-di-o-tolyl-1),2.4-diazadiphosphetidine (HCMDP) compounds have been carried out. The semiconducting properties of the investigated compounds were arising from electron­ delocalization via intramolecular interaction of p-electrons of (C=C) bonds and electron-donating groups in ortho positions. The conductivity was found to increase in the higher temperature range than in lower due to the trigonal bipyramidal structure which increases the possibility of electron­ delocalization and the interaction of p-electron system.

STRUCTURE AND VIBRATIONAL FREQUENCIES OF Ph3PCl2 WITH DISCRETE SOLVENT MOLECULES AND IN GAS PHASE

Triphenyldichlorophosphorane ( Ph 3 PCl 2) in solution was studied with cluster model of discrete water molecules and the Onsager reaction field model. The geometry of Ph 3 PCl 2– H 2 O cluster is optimized with DFT-PW91 and DZVP basis sets. A weak hydrogen bond is formed between Cl and H atom of the water molecule. The geometry data of Ph 3 PCl 2 molecule is altered due to the presence of water molecule. The bond length of P – Cl 2 increases from 2.501 Å to 2.832 Å, and the P – Cl 1 bond length decreases from 2.113 Å to 2.064 Å. Three C – P bonds have slightly changed. The geometrical parameters of the three benzene rings do not change much upon clustering. To compare with solution structure, gas structure of Ph 3 PCl 2 also was investigated. Four stationary structures were found. The trigonal bipyramidal structure C is a penta-coordinated structure and the most stable one. This is in agreement with the previous research. The trigonal bipyramidal structure C and the ionic structure A has no imaginary frequency. The structure B and structure D have an imaginary frequency of -41.9 cm-1 and -7.4 cm-1, respectively.

Synthesis and Structure of Pentaorganostannate Having Five Carbon Substituents

The reaction of spirostannabifluorene with methyllithium gave lithium pentaorganostannate, which is an intermediate of the transmetalation reaction on the tin atom and the first example of a stable pentaorganostannate having five carbon substituents. The X-ray structural analysis reveals its slightly distorted trigonal bipyramidal structure, the apical bonds of which have a considerable s character. The unique structure of the lithium pentaorganostannate is also discussed by the aid of theoretical calculations.

Synthesis, spectral and antimicrobial studies of triorganotin(IV) 3(2′-hydroxyphenyl)-5-(4-substituted phenyl) pyrazolinates

Triorganotin(IV) pyrazolinates of the type R3Sn(C15H12N2O · X) [where C15H12N2O · X = 3(2′-hydroxyphenyl)-5(4-X-phenyl)pyrazoline {where X = H (a); CH3 (b); OCH3 (c); Cl (d) and R = Me, Pr n and Ph}] have been synthesized by the reaction of R3SnCl with the sodium salt of pyrazolines in a 1 : 1 molar ratio, in anhydrous benzene. These newly synthesized derivatives have been characterized by elemental analysis (C, H, N, Cl and Sn), molecular weight measurement as well as spectral studies [IR and multinuclear NMR (1H, 13C and 119Sn)]. The bidentate behaviour of the ligands was confirmed by IR, 1H and 13C NMR spectral data. Trigonal bipyramidal structure around tin(IV) atom for R3Sn(C15H12N2O · X) has been suggested. The free pyrazoline and a few triorganotin(IV) pyrazolinates have also been screened for their antibacterial and antifungal activities. Some triorganotin(IV) pyrazolinates exhibit higher antibacterial and antifungal effects than free pyrazoline and some of the antibiotics.