A genetic locus (D1S58, detined by DNA probe pMCT118) that contains a variable number of tandem repeats (VNTR) has been successfully amplified from a very small amount of genomic deoxyribonucleic acid (DNA) by the polymerase chain reaction (PCR). The DNA sequence of the locus was determined and was found to consist of a 16-base consensus sequence and flanking sequences. Oligonucleotide primers complementary to the flanking sequences were synthesized to serve as primers for amplification of MCT118 by the PCR method. Human genomic DNA isolated from blood (2 ng from each sample) was successfully amplified at the MCT118 locus, and polymorphic bands were detectable by ethidium bromide staining after electrophoresis on polyacrylamide gels. Determination of genotypes at this VNTR locus can now be routinely achieved within 24 h, without the need for Southern blots or radioactive materials. Furthermore, the small size (387 to 723 base pairs) of the DNA fragments produced in the PCR amplification permits good resolution of individual alleles that differ by only one repeat unit. The precise specification of the number of tandem repeats present in each allelic fragment is reproducible from one analysis to another.

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Syntheses and characterizations of a Pd-based molecular triangle and square and hybrid composites with polyoxometalates are examined. The equilibrium between the Pd-based molecular triangle [(en*)Pd(4,4'-bpy)]3(NO3)6 and square [(en*)Pd(4,4'-bpy)]4(NO3)8 largely depends on the solvents, and both compounds have successfully been isolated: [(en*)Pd(4,4'-bpy)]3(NO3)6.3.5DMSO, monoclinic Cc (No. 9), a = 19.8210(2) A, b = 34.3667(5) A, c = 27.5484(4) A, beta = 89.9420(10) degrees , V = 18765.5(4) A3; [(en*)Pd(4,4'-bpy)]4(NO3)8, monoclinic C2/c (No. 15), a = 45.6921(16) A, b = 8.7721(8) A, c = 36.719(3) A, beta = 126.509(2) degrees , V = 11829.4(14) A3. The reactions of the Pd-based molecular triangle/square with [W6O19]2-, [W10O32]4-, and [alpha-SiW12O40]4- form [[(en*)Pd(4,4'-bpy)]4[ supersetW6O19]][W6O19]3, [[(en*)Pd(4,4'-bpy)]4[ supersetW6O19]](NO3)6, [[(en*)Pd(4,4'-bpy)]4[ supersetW10O32]][W10O32], [(en*)Pd(4,4'-bpy)]4[W10O32]2, and [(en*)Pd(4,4'-bpy)]4[alpha-SiW12O40]2. The molecular square does not encapsulate the largest [alpha-SiW12O40]4-, but it does encapsulate [W6O19]2- and [W10O32]4-. The isolation of [W6O19]2- and [alpha-SiW12O40]4- from the mixture by use of the molecular square is possible by utilizing the quite different solubility of [[(en*)Pd(4,4'-bpy)]4[ supersetW6O19]](NO3)6 and [(en*)Pd(4,4'-bpy)]4[alpha-SiW12O40]2 formed in DMSO. The size-selective encapsulation property of supramolecules may open the new way to rationalize isolation methods of the useful polyoxometalates.

Reactions of (en*)Pd(NO(3))(2) (en* = N,N,N',N'-tetramethylethylenediamine)with a series of organic bridging ligands of pyrazine, 1,2-bis(4-pyridyl)ethylene, 1,2-bis(4-pyridyl)acetylene, and 1,4-bis(4-pyridyl)benzene are carried out to investigate factors controlling the supramolecular structures and the equilibrium between the molecular triangles and the squares in solutions. The molecular structures of solid triangular [(en*)Pd(L(n))](3)(NO(3))(6) with 1,2-bis(4-pyridyl)ethylene and 1,2-bis(4-pyridyl)acetylene bridging ligands are determined by X-ray crystallography: [(en*)Pd(1,2-bis(4-pyridyl)ethylene)](3)(NO(3))(6), monoclinic Pn (No. 7), a = 17.3242(3) A, b = 15.0804(3) A, c = 17.3223(3) A, beta = 103.5100(10) degrees , V = 4400.33(14) A(3), Z = 2; [(en*)Pd(1,2-bis(4-pyridyl)acetylene)](3)(NO(3))(6), orthorhombic Aba2 (No. 41), a = 14.6642(3) A, b = 27.8763(5) A, c = 21.4233(4) A, V = 8757.5(3) A(3), Z = 4. In contrast, an infinite chain structure of {[(en*)Pd(pyrazine)](NO(3))}(infinity) (monoclinic P2(1)/m (No. 11), a = 14.4740(7) A, b = 8.9209(3) A, c = 28.9705(13) A, beta = 89.974(2) degrees , V = 3740.7(3) A(3), Z = 2) is observed with the shortest pyrazine. The steric hindrance between the supporting and the bridging ligands or the neighboring supporting ligands would contribute to the formation of the infinite chain complex 1. The N(Py)-Pd-N(Py) angles in the solid molecular triangles monotonically increased closely to 90 degrees with the increase in the lengths of the bridging ligands, indicating the relaxation of the steric hindrance between the supporting and the bridging ligands. The structures of the molecular triangles and squares in solutions are optimized with density functional theory (DFT) calculations using the conductor-like polarizable continuum model (C-PCM), and the resulting structures are almost the same as those in the solid state. The (1)H NMR spectra indicate that (i) the equilibrium between the molecular triangles and the squares is attained upon the introduction of the methyl substituents into the en supporting ligands (en*), (ii) the DeltaG degrees values decreased with the increase in the lengths of the straight bridging ligands, and (iii) the equilibrium constants depend on the kinds of solvents. The (1)H NMR spectra estimated with the gauge invariant atomic orbital DFT (GIAO-DFT) calculations well reproduce the experimental data, and the single-point energy DFT calculations with C-PCM in the presence of the solvents approximately reproduce the facts (i)-(iii).