Volume 36, Issue 3-4

There are over 30 heterotetranuclear complexes of the types Pt 3 M (10 examples), Pt 2 M 2 (15 examples), PtSn 3 (5 examples), Pt 2 NaAg, PtSn 2 Fe (2 examples) and PtSnHgGe (1 example) (M=non-transition metal) for which structural parameters are available. These were analyzed and classified. The inner coordination sphere about the Pt atom ranges from three to seven, with the most common one being square planar, whereas three (Y-shaped) and seven (4+3) are rarities. The M atoms are three- (Y-shaped; Li, Sn, Tl, Hg), four- (tetrahedral; Li, Ge, Sn, Hg), five- (mostly trigonal bipyramidal; Sn, Zn, Hg), and six-coordinate (pseudo-octahedral; Na, Sn, Tl, Cd). The mean Pt-M bond distance increased in the order 2.435 Å (M=Ge)<2.645 Å (Sn)<2.676 Å (Zn)<2.822 Å (Hg)<2.827 Å (Li)<2.833 Å (Pb)<2.898 Å (Tl)<2.960 Å (Cd). The data are compared and discussed with those found in heterodimers and heterotrimers.

There are 18 heteropentanuclear Pt 4 M (×5), Pt 3 M 2 (×3), Pt 2 M 3 (×2), PtM 4 (×5), Pt 3 HgRe, Pt 2 Ge 2 Hg, and Pt 2 Fe 2 Tl and 14 heterohexanuclear Pt 4 M 2 (×5), Pt 2 M 4 (×5), PtM 5 (×2), Pt 2 Co 2 Na 2 , and PtOs 3 Sn 2 (M=non-transition metal) complexes for which structural data are available and were classified and analyzed. These complexes crystallized in the following crystal classes: monoclinic (48.5%)>triclinic (31%)>orthorhombic (10%)>cubic, trigonal and tetragonal each (3.5%). The inner coordination spheres about Pt atoms are three- (Y shape), four- (square planar), five- (trigonal bipyramidal), six- (pseudo-octahedral), and seven-coordinated (4+3), whereas the former (three) and the last one (seven coordinated) are rarities. The square planar by far prevails [Pt(II) and pseudo-octahedral (Pt(IV)]. The M atoms are two- (Tl), three- (Hg), four- (tetrahedral) (Li, Ge, Sn, In, Sb, Zn, Cd, and Hg), six- (Na), and eight- (Tl) coordinated. The mean Pt-M bond distance elongated in the order 2.435 Å (M=Ge)<2.440 Å (In)<2.530 Å (Sb)<2.640 Å (Li)<2.680 Å (Pt)<2.708 Å (Sn)<2.763 Å (Hg). The most common bonding atom is μ 3 -S, and the mean M-μ 3 S bond distance elongated in the order 2.37 Å (Pt)<2.385 Å (Zn)<2.555 Å (Cd)<2.62 Å (Hg)<2.765 Å (Tl). Several relationships were found and discussed.

The synthesis of the 2,8-dioxa-5-aza-1-stanna-bicyclo[3.3.0 1.5 ]octane [PhN(CH 2 CH 2 O) 2 Sn] n ( 3 ) by a combined ligand exchange/redox reaction and independently by the reaction of tin(II)butoxide with N -phenyldiethanolamine is reported. Compound 3 was characterized by elemental analysis and single crystal X-ray diffraction analysis. In the solid state, it is a coordination polymer via intermolecular O→Sn interactions at O-Sn distances of 2.325 (3) and 2.379 (3) Å. The intramolecular N→Sn interactions at distances of 2.818 (3) and 3.096 (3) Å are rather weak.

Four new di- and triorganonitrato stannate complexes and related derivatives have been synthesized and characterized by infrared and Mössbauer spectroscopy. The structure of Et 4 N[NO 3 (SnClPh 3 ) 2 (SnPh 3 NO 3 )] ( 1 ) has been determined by single-crystal X-ray diffraction analysis. In the trinuclear organostannate complex, each Sn IV atom is five-coordinated and adopts a trigonal-bipyramidal trans -OXSnC 3 (X=O or Cl) geometry. The overall coordination environment of the Sn IV atoms is trans-octahedral for 2 and 3 or cis-trigonal-bipyramidal for 4 . In the related derivatives, the NO 3 - anions behave as monodentate ligands.

The biologically important complexes of aluminium(III) and gallium(III) derived from 1-acetylferrocenehydrazinecarbothioamide (L 1 H) and 1-acetylferrocene carbodithioic acid (L 2 H) were prepared and investigated using a combination of microanalytical analysis, melting point, electronic, infrared, 1 H NMR and 13 C NMR spectral studies along with X-ray powder diffraction studies. Aluminium and gallium isopropoxides interact with the ligands in molar ratios of 1:1, 1:2 and 1:3 (metal:ligand), resulting in the formation of coloured products. The ligands are coordinated to aluminium(III) and gallium(III) via the azomethine nitrogen atom and the thiolic sulfur atom. On the basis of X-ray powder diffraction study, one of the representative gallium(III) complexes was found to have orthorhombic lattice, having the following lattice parameters: a=8.9200, b=14.6000 and c=7.0000. On the basis of the above studies, for the aluminium(III) and gallium(III) complexes, pentacoordinated structure for 1:1 complex and hexacoordinated structure for 1:2 and 1:3 complexes were assigned. The antimicrobial activities of the ligands and complexes were screened in vitro against bacteria Pseudomonas cepacicola and Bacillus substilis and fungi Collectatrichum capsici and Fusarium oxysporum . The complexes have higher activities than the free ligands do. In vivo studies of the ligands and their corresponding complexes have also been carried out to assess their antifertility activity. The results of these activities indicate the antiandrogenic nature of these complexes.

A novel family of tetraazamacrocyclic complexes of Sn(II) has been synthesized by template condensation using 1,9-diaminononane with different dicarboxylic acids (malonic, succinic, glutaric, and adipic). The complexes were characterized by elemental analysis, conductivity measurements, molecular weight determinations, infrared (IR), proton nuclear magnetic resonance ( 1 H NMR), carbon nuclear magnetic resonance ( 13 C NMR), and tin nuclear magnetic resonance ( 119 Sn NMR) spectral studies. The compounds were found to be monomeric in nature, having an octahedral geometry. The in vitro antibacterial activity of macrocyclic complexes against Escherichia coli and Staphylococcus aureus were tested to assess their inhibiting activities. The antifungal activity of starting materials and their metal complexes were studied by screening the compounds against Fusarium oxysporum and Aspergillus niger . The testicular sperm density, sperm morphology, sperm motility, density of cauda epididymis, spermatozoa, and fertility in mating trials and the biochemical parameters of the reproductive organs of the rats were examined and are discussed.

Some Schiff’s base complexes of aluminum(III) of the type (CH 3 COCHCOCH 3 ) 2 Al(µ-OPr i ) 2 AlL n (OPr i ) 2-n [where LH=OHC(R)=CHC(R′)=NC 6 H 5 ; R=R′=CH 3 ,C 6 H 5 ; R=CH 3 , R′=C 6 H 5 ; LH=C 6 H 4 (OH)CH=NC 6 H 5 and n=1 or 2] were prepared and characterized by various spectroscopic techniques. The molecular weight measurements indicated their binuclear nature. The 27 Al nuclear magnetic resonance spectra of representative compounds [(CH 3 COCHCOCH 3 ) 2 Al(µ-OPr i ) 2 Al{OC(C 6 H 5 )=CHC(C 6 H 5 )=NC 6 H 5 }(OPri)] [3] and [(CH 3 COCHCOCH 3 ) 2 Al(µ-OPr i ) 2 Al{OC(CH 3 )=CHC(CH 3 )=NC 6 H 5 } 2 ] [6] suggest the presence of aluminum(III) atoms in different coordination states.

A new lead complex, {[Pb(4-sb)(phen)](4,4′-bipy) 0.5 } n (1) (where 4-sb=4-sulfobenzoate dianion, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine), was synthesized and characterized by single-crystal X-ray, infrared, and thermogravimetric analyses and fluorescence studies. In this compound, the lead atom is hexacoordinated by two N atoms of one phen ligand and four O atoms from three 4-sb dianions. Each 4-sb serves as a bridging ligand, connecting adjacent Pb II atoms into a centrosymmetric polymeric chain. Intermolecular π-π interactions and hydrogen bonds are observed in the complex, which stabilize the crystal packing and give rise to three-dimensional architecture.

Cd(II), Hg(II), Pb(II), Sn(II) and Ca(II) complexes of curcumin have been prepared and characterized on the basis of their analytical, spectral and conductance data. In all the complexes, curcumin behaved as a monobasic bidentate ligand in which the intramolecularly hydrogen-bonded enolic proton is replaced by the metal ion. The antifungal (with Aspergillus niger, Aspergillus flavus, Aspergillus heteromorphus and Penicillium verruculosum ) and antibacterial (with Bacillus cereus ) studies reveal that metal complexation considerably increased the activity of curcumin, and among the complexes, Sn(II) complex exhibited maximum activity except for A. flavus where Hg(II) complex is more active.

Single crystal X-ray crystallography revealed that the title compound [(4-Me 2 N)(3-O 2 N)C 6 H 3 ] 2 TeCl 2 is associated in the solid state mainly by intermolecular secondary Te‧‧‧O contacts.

A new bulky secondary amine, HN(Dip){C(H)Ph 2 } (Dip=C 6 H 3 Pr i 2 -2,6), has been prepared. This and a related amine, HN(Dip)(Mes) (Mes=mesityl), have been utilized in the formation of bulky lithium amides, which when added to a source of GeCl 2 have yielded two new, bulky bis(amido)germylenes, [Ge{N(Dip)(Mes)} 2 ] and [Ge{N(Dip)[C(H)Ph 2 ]} 2 ], both of which have been crystallographically characterized and shown to be two-coordinate monomers.

The title compound Sn 2 Cl 6 (OEt) 2 (HOEt) 2 , accidentally obtained as a side product from the reaction of 2,6-Mes 2 C 6 H 3 Li with SnCl 4 in Et 2 O, was investigated by single crystal X-ray diffraction.

Heating of the arylstibonic acid [2,6-Mes 2 C 6 H 3 Sb(O)(OH) 2 ] 2 in refluxing ethanol gave rise to the esterification and formation of the monoethyl ester [2,6-Mes 2 C 6 H 3 Sb(O)(OEt)(OH)] 2 , the molecular structure of which was established by X-ray crystallography.

The salt metathesis reaction of 1,8-dilithionaphthalene with tributyltin chloride provided 1,8-bis(tributyltin)naphthalene ( 1 ) in 41% yield. The transmetallation of 1 with tin tetrachloride gave rise to the formation of 7,7,14,14-tetrachlorodinaphtho[1,8 bc :1′,8′- fg ][1,5]distannocine ( 2 ) in 75% yield. The molecular structure of 2 ·2 H 2 O·4 THF was established by single crystal X-ray crystallography.